Complex Analysis for Math Engineering

Bring math to life with this exciting new math activity book for kids.With 30 activities and crafts that children can play their way through, this kids’ book takes the fear out of math―and gives you t

DKfindout! Engineering opens up the amazing world of engineering for kids with beautiful photography, lively illustrations, and key curriculum information. The DKfindout! series will satisfy any child

Explore the exciting world of dinosaursWhether you’re a dinosaur fan or just simply enjoy practical, hands-on projects, this book combines creativity with a prehistoric twist. Each of the super-fun make-and-do projects in this book comes with simple step-by-step photographs and instructions that will inspire imaginative minds and bring the dinosaur world to life! Perfect for kids who are interested in STEM (science, technology, engineering, and math), Dinosaur Lab features activities that cover many aspects of prehistoric life, from the evolution of dinosaurs to what might have caused them to die out. You’ll combine science and math with art and craft by making your own dinosaur fossils; constructing a 3-D diorama to learn about the Triassic, Jurassic, and Cretaceous eras; designing a fearsome Triceratops mask; hatching your own mini dinosaur out of a bath bomb; and even creating a meteorite-impact experiment to find out how dinosaurs may have become extinct! Throughout the book, there

DK’s best-selling richly illustrated encyclopedia series explores the wonderful world of transport. Knowledge Encyclopedia: Transport! uses incredibly detailed 3D illustrations to show children aged 9+ everything they need to know about how vehicles work. Children will find themselves totally absorbed in complex subjects with the Knowledge Encyclopedia series, made clear through engaging explanations, intricate illustrations, vivid photographs, and striking 3D images.Meet hundreds of vehicles that float, fly, or speed across the land, including the record breakers - the fastest, largest, longest, and strangest modes of transportation ever to zoom, sail, or soar. This all-encompassing encyclopedia for kids offers:- A whole collection of facts, charts, timelines, and illustrations that cover a vast range of transportation. - Complex subjects that are explained using amazingly detailed CGIs that entice young readers to dive in and explore.- A visual approach using illustrations, photograp

The perfect introduction to poetry, The Poetry Book offers a fascinating exploration of more than 90 of the world's greatest poetic works.Discover poems in all their many guises, from the epics of the ancient world through Renaissance sonnets to modernist masterpieces such as The Waste Land, and the key works of the last 50 years, including And Still I Rise by Maya Angelou and Derek Walcott's Omeros.Using the Big Ideas series' trademark combination of clear explanation, witty infographics, and inspirational quotes, The Poetry Book unlocks the key ideas, themes, imagery, and structural techniques behind even the most complex of poems, in clear and simple terms, setting each work in its historical, social, cultural, and literary context.Dive into the passionate world of poetry to discover:COMPREHENSIVE: Brings together a curated selection of the most celebrated and important poems ever written, majoring on English-language poetryANALYTICAL: Provides critical analysis of form, structure,

From reproduction to respiration and from enzymes to ecosystems, this guide makes complex topics easy to grasp at a glance. Perfect support for home and school learning.Each topic is fully illustrated

DK’s best-selling illustrated encyclopedia series takes you back to the Mesozoic Era, when fearsome dinosaurs roamed the land, sea, and skies. Discover dinosaurs as you've never seen them before through jaw-dropping 3D illustrations in this dinosaur encyclopedia for kids ages 9+. Did you know that Velociraptor had three large "killer claws" on each foot to hunt down prey? Or that the long-necked Diplodocus was as long as three school buses? Can you imagine what a strange life it would be for Saltasaurus with no toes on its front feet? Would you believe that Carcharocles megalodon was an ocean monster with a fearsome bite at least six times stronger than today's great white shark?Knowledge Encyclopedia’s clear explanations, illustrations, photographs, and 3D images will engage children in complex subjects.Find yourself transported to the age of dinosaurs and then the Ice Age with this perfect gift for anyone who loves dinosaurs and prehistoric creatures. This all-encompassing dinosaur e

DK’s best-selling illustrated encyclopedia series explores the fantastical world of myths and legends. Discover stories from myth and legend as you've never seen them before through incredibly detailed 3D illustrations in this encyclopedia for children aged 9+. Knowledge Encyclopedia’s clear explanations, illustrations, photographs and 3D images will engage children in complex subjects.Find yourself transported to a realm of myth and legend with this perfect gift for anyone who loves stories of gods, monsters and heroes. This all-encompassing myth encyclopedia for kids offers:An impressive collection of facts, charts, timelines and illustrations. A visual approach using illustrations, photographs and extremely detailed 3D CGI images.Clear explanations and retellings of different myths and legends from around the world. Children can explore mythology in a new and exciting way through spectacular computer-generated images of key heroes, gods, monsters and locations. This new book in the

DK’s best-selling richly illustrated encyclopedia series explores the wonderful world of science. Learn the ins and outs of science as you’ve never seen it before, through incredibly detailed 3D illustrations, in this encyclopedia for children aged 9+. Knowledge Encyclopedia’s clear explanations, illustrations, photographs, and 3D images will engage children in complex subjects.This impressively detailed encyclopedia uses awesome illustrations to show biology, chemistry, and physics in the world around us. This all-encompassing science encyclopedia for kids offers:An impressive collection of facts, charts, timelines and illustrations. A visual approach using illustrations, photographs and extremely detailed 3D CGI images.Clear explanations of physics, chemistry, and biology, as well as space exploration, the latest technology, wonderful wildlife, and our amazing bodies. Children can explore science in a new and exciting way. Learn about groundbreaking topics like looking inside a cell,

Change the way you see the world, with a groundbreaking visual approach to the wonders of our planet, in this fully updated edition. Explore the universe, from the inside of an atom to black holes, then discover the explosive science behind a fireworks display. This fully updated third edition of Knowledge Encyclopedia will continue to fascinate young readers with its microscopic detail and amazing facts on a huge range of topics.Children aged 9+ will find themselves totally absorbed in complex subjects, made clear through engaging explanations, intricate illustrations, vivid photographs, and striking 3D images. From Viking raiders and Samurai warriors to robotics and chemical reactions, amazing animals, the human body, the marvels of history, and more are visualised in incredible detail, inside and out, providing a mind-blowing introduction to every aspect of human knowledge. This all-encompassing encyclopedia for kids offers: - A whole collection of facts, charts, timelines, and illu

This book explains and explores the essential terms and key concepts in the world of business, finance, and company management. If you're perplexed by profit margins, confused by cash flow, or baffled by balance sheets, all your questions and many more are answered in this indispensable guide. Grasp how companies work, from management to research and development, and sales and marketing to production and distribution. Eye-catching visual aids give a helpful representation of each and every aspect of business, while the complex subject matter is broken down into clear definitions and concise explanations, expressed in easy-to-understand language. Crammed with essential know-how, How Business Works is perfect for anyone looking to boost their business brain or learn the ropes from the ground to the top.

Use your eyes, ears, and imagination to explore your amazing mind and sharpen your wits. Want to paint like a prodigy, experiment like a scientist, or even invent the next new technology? Put your grey matter to the brain-training test and see how you measure up to some of the greatest thinkers in history. Tackle brain-boggling puzzles, games, and optical illusions and discover what makes your brain work: from why you smile to what is going on inside your head and what side of your brain does what.Learn about neurons, how memory works and how to boost your creativity. This book makes a complex subject fun, accessible and exciting, and is perfect for any child, whether they are intent on becoming a genius or just want to have fun with clever activities at home, on a journey or in school.

Packed with infographics and flowcharts that explain complex concepts in a simple but exciting way, this book is the perfect pocket-sized introduction to politics and political thought.From the origin

Did the universe start with a Big Bang? Is light a wave, a particle – or both? Is a "Theory of Everything" possible?Explaining the key milestones in the field of science in a clear and simple way, The Science Book answers these questions and more besides, and is the perfect introduction to the subject. Untangling knotty theories and shedding light on abstract concepts, entries unpack each complex idea with a combination of easy-to-follow explanations, innovative graphics, and intriguing quotes.Discover the most important theories of history’s greatest scientists, why Copernicus’s ideas were so contentious, how Einstein developed the concept general and special relativity, and the reasoning behind Crick and Watson’s proposed structure for DNA, and much more besides.Fully revised and updated with eight brand-new pages of content, The Science Book is a truly accessible and comprehensive route into a fascinating subject. Packed with scientific quotations, profiles of key figures and discov

How do our minds influence the way we behave? How do our bodies and minds work together? Do we have free will?Exploring and explaining the big ideas and groundbreaking theories in psychology clearly and simply, The Psychology Book answers these questions and more and is the perfect introduction to the subject. Untangling knotty theories and shedding light on abstract concepts, entries unpack each complex idea with easy-to-follow explanations and eye-catching images.In this book, you can find:The history of psychology, from its roots in philosophy to modern studies of autism and psychiatry across all of the key fields of study, from psychotherapy to cognitive psychology and behaviourism.Groundbreaking ideas of great thinkers, from Sigmund Freud and Carl Jung to Noam Chomsky and Daniel KahnemanInformation about the key personalities of the 19th and 20th centuries whose work has significantly contributed to our understanding of human behaviour.With millions of copies sold worldwide, The P

Get to grips with the concepts that shaped the way we think about ethics, politics, and our place in the universe.Explaining the big ideas and groundbreaking theories of key philosophers in a clear and simple way, The Philosophy Book is the perfect one-stop guide to philosophy and the history of how we think. Untangling knotty theories and shedding light on abstract concepts, entries explore and explain each complex idea with a combination of easy-to-follow explanations and innovative graphics.Explore the history of philosophy, from ancient Greece and China to today, and find out how theories from over 2,000 years ago are still relevant to our modern lives. Follow the progression of human ideas and meet the world's most influential philosophers - from Plato and Confucius through René Descartes and Mary Wollstonecraft to Ludwig Wittgenstein, and Judith Butler.Fully revised and updated, with quirky illustrations, clear explanations, a philosopher directory, and a glossary of key vocabula

Get better at maths and numbers by realizing which math skills you already use in daily life, and learn new ones while having fun. Did you realize how much maths you are already using when playing computer games, planning a journey, or baking a cake? This book shows how to expand the knowledge you've already got, how your brain works things out, and how you can get even better at all sorts of maths. Explore amazing algebra, puzzling primes, super sequences, and special shapes.Challenge yourself with quizzes to answer, puzzles to solve, codes to crack, and geometrical illusions to inspire you, and meet the big names and even bigger brains who made mathematical history, such as Pythagoras, Grace Hopper, and Alan Turing. Whether you're a maths mastermind, numbers nerd, or completely clueless with calculations, train your brain to come out on top. This essential book explains the basic ideas behind maths, to give young readers greater confidence in their own ability to handle numbers and m

Discover the rich and complex history of the peoples of Africa, and the struggles and triumphs of Black cultures and communities around the world. With profiles of key people, movements, and events, The Black History Book brings together accounts of the most significant ideas and milestones in Black history and culture. This vital and thought-provoking book presents a bold and accessible overview of the history of the African continent and its peoples - from the earliest human migrations to modern Black communities and the African diaspora. Powerful images and innovative infographics bring to life the stories of the early kingdoms of Ancient Egypt, Nubia, and Carthage; the powerful empires of the Medieval and Early Modern eras; and the struggle against European colonizers. Black history and culture beyond the African continent is also explored in detail - including the Atlantic Slave Trade; the quilombos (slave resistance camps) of Brazil; the Harlem Renaissance and Jazz Age; the "Wind

About The Aircraft BookTake an action-packed flight through the history of aircraft and the intrepid pioneers who made a dream become reality.Uncover the engineering behind more than 800 aircraft models, from military jets to commercial planes. This visual history book captures the fascinating story of aeroplanes and aviation, and how this groundbreaking discovery has influenced the 21st Century.Inside the pages of this aircraft book, you'll discover:- The history of military and commercial aircraft from all over the world, decade by decade, to the present day in stunning visual detail- Comprehensive catalogues highlighting the most important aircraft of each period along with their specifications and unique features- Showcases particularly celebrated aircraft - such as the Supermarine Spitfire and Concorde - in beautifully photographed "virtual tour" features- Tells the stories of the engineers and manufacturers that created marques like Boeing and AirbusModern flight has opened the w

This is the definitive narrative history of the people, politics, and events of the Second World War - the epic conflict that shaped the modern worldFrom the build-up to the fighting, through to the reverberations still felt in the aftermath, this is a compelling, accessible, and immediate history of the war, perhaps the most complex, frightening, and destructive event in world history. Discover how deep-seated local fears and hatreds escalated into one vast global conflict that was fought out to the bitter end - from the rise of Hitler and the Nazi party to Pearl Harbor, the D-Day landings, and Hiroshima. And find out how key battles, political and economic forces, individual leaders, and technological advances influenced the course of the war.Packed with images, including rarely seen images and unforgettable first-person accounts, A Short History of World War II is a uniquely accessible account of history's most devastating conflict.

Meet fan favourites Stitch, Angel, Leroy, and Scrump in this awesome glow-in-the-dark sticker activity book, featuring over 100 stickers!Join Stitch and friends in this vibrant glow-in-the-dark sticker book, filled with pictures and facts about fan-favourite characters, along with over 100 glow-in-the-dark stickers to use in the book – or wherever you like!Enjoy some glow-in-the-dark sticker fun with Disney’s Stitch:*MORE THAN 100 STICKERS: Perfect for decorating bags, pencil cases, and other belongings*FULL OF IMAGES, FUN FACTS, & ACTIVITIES: Flip through pages featuring plenty of sticker-filled activities, lively images, and fact-packed information about Stitch and friends*A UNIQUE DISNEY STICKER BOOK FOR KIDS: Perfect for young Disney fans and gift buyers looking for delightful Disney gifts for kidsWith the Disney Stitch Glow in the Dark Ultimate Sticker Book, kids can have a blast with Stitch facts, artwork, and plenty of glow-in-the-dark stickers.

Follow our ever-changing skies and uncover the secrets of weather with this picture-packed meteorology book for kids.DK's best-sellingEyewonderseries is back and has been refreshed for the next generation of young readers ages 5-7.Get ready to chase the wind, ride the waves, and dodge lightning as you dive into this book about weather for children. Study the fascinating forces that shape weather and find out how clouds form, what makes thunderstorms rumble, and why the weather changes every season.This picture-led reference guide will take you on a visual tour of the changing weather. Stay-at-home explorers will feel inspired by the dramatic photographs, up-to-date information, fact-packed pages and a brand-new "eyewonder" feature with fascinating weather stories, where knowledge meets real-world application.In this newly revised weather book for kids, you'll find:Fully updated and revised content for children starting to develop a passion for science.Eye-catching photographs that grab

A beautiful field guide to flowers featuring notes, spectacular photos, and colourful illustrations of the world’s most fascinating flowers.A compact version of DK’s bestselling anthology series,An Anthology of Flowersis perfect for young botanists and nature enthusiasts ages 7-9 to take on the go and find the beauty in the blooms.An Anthology of Flowerswill be your child’s guide through the natural world, teaching how to easily identify different species, including a vast variety of blooms, from exotic blossoms to iconic garden favourites.This stunning flower book for kids offers:The next book in the new compact spin-off of the bestselling Children’s Anthologies series.A magnificent collection of over 100 unique flowers, from wildflowers and garden favourites to rare species.A quality gift book, with metallic foil and striking imagery on every page.An Anthology of Flowersfeatures mesmerising images, beautiful illustrations by the artist behind DK’s bestselling Anthology series and cap

Discover how to identify flowers, where to find them, and other details about more than 100 flowers from around the world. Compact in size yet brimming with information, An Anthology of Flowers explores a vast variety of blooms, from exotic blossoms to iconic favorites. Learn to easily identify different species using detailed annotations, vivid illustrations, and unique descriptions of each flower. Featuring colorful photographs and vibrant illustrations, this book is a treasure trove for budding botanists, nature enthusiasts, and curious readers seeking an informative flower identification book. Whether you're out exploring or flipping through its pages at home, An Anthology of Flowers is sure to bring the natural world to life.

Get ready to hop into action with Mabel and King George! Uncover the mysteries of the animal world as Mabel and her friends use technology to communicate with animals. This colorful sticker book features all your favorite characters (in their human and animal form) from the movie. With over 100 stickers to use, Disney Pixar's Hoppers The Ultimate Sticker Book will keep kids entertained for hours!

A beautiful field guide to the stars featuring notes, spectacular photos, and colourful illustrations of all 88 constellations. A compact version of DK’s bestselling anthology series, An Anthology of Stargazing is perfect for young astronomers and stargazers ages 7-9 to take on the go and uncover the secrets of the stars. An Anthology of Stargazing will be your child’s guide through the stars, teaching all about the intricate star patterns, the brightest stars, fascinating asterisms, and the legends woven through the night sky, from both the Northern and Southern Hemispheres.This stunning book about stars and constellations for kids offers:The next book in the new compact spin-off of the bestselling Children’s Anthologies series. A magnificent collection of all 88 constellations recognised by the International Astronomical Union, and asterisms. A quality gift book, with metallic foil and striking imagery on every page.An Anthology of Stargazing features mesmerising images, beautiful il

Join these unlikely partners as they learn how to work together on another adventure to save the day and their city. Part of a new series of official Disney graphic novels!Journey beyond the movies as the charming cast of Zootropolis 2 take on new adventures, which see ZPD officers Hopps and Wilde team up on their mission to make the world a better place! Whatever they are dealing with, Judy and Nick realise that not every case is the biggest, but they are all important. A bold and colourful adventure book for kids aged 5-9:Perfect for early readers, The New Adventures of Disney Zootropolis 2 invites kids to embrace the joy of reading in an engaging graphic novel formatBeautiful illustrations and an engaging story make the entry into reading accessible and funPart of a new series of graphic novels featuring popular Disney characters – don’t miss the rest of the series!Embark on New Adventures with more beloved Disney characters:The New Adventures of Disney Zootropolis 2The New Adventur

This glorious guided tour of cartographic history features more than 300 of the most famous and important maps of all time. Immerse yourself in ancient Chinese star charts, decipher medieval Mappae Mundi, and marvel at intricate surveys of the ocean floor and the lunar surface. Discover how Polynesian navigators used sticks to chart their way across the Pacific, what a rhumb line is, and where dragons were once said to lurk.Organized chronologically, the book includes the most celebrated examples of maps spanning more than 5,000 years, explaining everything from scales and compasses to meteorological symbols, and exploring techniques from engraving and printing to cartographic projection. Entries also place the maps in their wider cultural and historical context, providing a complete overview of the subject. Combining stunning reproductions with precise annotation, visual analysis, and pull-out details, Maps, Annotated brings an expertly curated selection of the world’s most celebrated

Unlock the secrets behind everyday items and extraordinary inventions with exploded artworks and photographs that reveal the materials used to create everyday objects. Finding out What's It Made Of? is just the start of an amazing journey into the world of materials science, in this non-fiction book for science enthusiasts aged 9-12. Learn about the surprising properties of materials and how they are put to thousands of different uses, from sneakers to smartphones and game controllers to glue.This fascinating book reveals the secrets of many everyday objects, and a few more unusual ones. This science book for curious children offers: A breakdown of everyday and futuristic objects, revealing what goes into a range of common and cutting-edge items - from game controllers to space suits!Hyperrealistic artworks and vivid photos show each component and object up close and in incredible detail. STEM learning that supports classroom material science by showing how the properties of different

An interactive board book with hidden reindeer and winter animal surprises along with way! Tactile elements and delightful imagery will encourage the development of motor skills and early learning. Babies and toddlers will love lifting the big flaps to find five peekaboo surprises pop up from the pages, including Parker Polar Bear and Percy Penguin, making this board book a fun and easy story about winter animals. Pop-up Peekaboo! Reindeer provides lots of opportunities for parent-and-child interaction and hours of wintry fun.Journey through the snow and watch as a Rosie Reindeer finds each of her friends, wraps up warm and puts on her favourite boots. This winter pop-up book for 3-5 year olds includes:Hands-on play elements that build all-round learning skills. 5 flaps throughout the book to lift and find the pop-ups, helping to develop fine motor skills.Rhythmic, read-aloud text that aids language development. Rounded edges and chunky board book pages rigorously tested (and chewed) b

A bumper book for little learners that’s bursting with facts about the animal kingdomThis exciting introduction to animals is brimming with facts about the diverse wildlife that inhabits our extraordinary planet.From peacocks and frogs to sharks and dogs, this book is a perfect companion for young, curious minds that are eager to learn all about different animals and where they live.Delve into the world of these majestic creatures and learn about their diets, habits, and our own connection to the animal kingdom. Through this engaging visual guide, children will not only gain knowledge about the animals that coexist with us on Earth, but also understand the importance of protecting the rich biodiversity that surrounds us.Filled with fun facts and colourful illustrations, My Encyclopedia of Very Important Animals will feed your imagination and quench your thirst for knowledge.

Celebrate the festive season with Pok幦on. Packed with cool facts and awesome activities--it's the perfect present for the ho-ho-holidays! Discover the Pok幦on who love a sparkly surprise, can rustle up a feast, or will make you shiver with their icy skills. Have fun spotting Squirtle in a snowball fight, or Pikachu in a cute woolly hat. Plus, you can test your Pok幦on skills with cool quizzes, puzzles, and games. Pok幦on Happy Holidays has everything you need to make the winter season even more merry!

Find Rosie Reindeer and her cuddly friends hiding behind flaps and popping up from the pages in this delightful book for little ones. Rosie Reindeer wants to go outside to play in the snow. But who can she find to join her and where is her sledge? Babies and toddlers will love lifting the big flaps to play peekaboo with Parker Polar Bear, Peter Penguin, Harry Husky, and Sophie Seal as they get ready to have fun in the snow. Rosie Reindeer finds each of her friends, she wraps up warm, puts on her favorite red wellies, and goes outside. Now it's time for Rosie Reindeer's friends to find her! The lively, read-aloud rhymes in this book encourage literacy and early learning, while the surprise pop-up characters will delight curious preschoolers. With the help of parents or caregivers, toddlers will have fun turning the sturdy board book pages and lifting the flaps to find Rosie Reindeer and her cuddly winter friends. Ideal for interactive preschool play, Pop-up Peekaboo! Reindeer will appea

Delight your little one with five pop-up surprises featuring Toy Story characters in this delightful board book!It?s playtime with the Toy Story pals! Join Woody, Bo Peep, Buzz Lightyear, Jessie, and their friends in this pop-up and flaps board book for curious little ones who love Toy Story and Disney and Pixar movies. Little hands can lift big flaps and see five peekaboo surprises pop up from the pages, and explore themes of friendship, teamwork and bravery. This interactive pop-up book for 0-3 year olds includes:Hands-on play elements that build all-round learning skills.Lift the 5 flaps throughout the book to find the pop-ups, helping to develop fine motor skills. Rhythmic, read-aloud text that aids language development. Rounded edges and chunky board book pages rigorously tested (and chewed) by toddlers.Ideal for interactive preschool play, Pop-Up Peekaboo! Disney and Pixar Toy Story will appeal to both parents and children and is certain to keep little ones entertained time and t

Discover a wealth of wildlife, natural wonders and lively cities by heading down under and exploring Australia. DK Super World: Australia is part of the new DK Super World series for children aged 7-11 to explore the wonders of diverse cultures and landscapes across the globe. Aligned with England’s National Curriculum, Cambridge Primary and the IB PYP, this book is the perfect support for learning about the countries of the world.Embark on an educational journey with this enriching Australia country profile book, specifically tailored for primary school pupils. This learn-to-read book for children offers:Curriculum-aligned and age-appropriate material that covers all the key teaching points. Bright images, engaging content and interactive elements that helps encourage reluctant learners.Vocabulary-building content covering a wide range of topics. Captivating and curriculum-aligned content, diagrams and interactive elements provide an immersive learning experience while covering key in

Uncover the secrets of catching Pok幦on, in this Level 2 Super Reader!Ready, set, catch! Discover top Trainer tips on how to find and catch Pok幦on. Learn about perfect partners, such as Captain Pikachu and Friede. Identify Pok幦on with Liko and Roy. Plus, meet the Pok幦on Professors and Trainers who will help you be the very best!Packed with colorful Pok幦on imagery, clear and simple vocabulary, and a fun quiz, this thrilling Level 2 DK Reader will help young readers build their reading abilities and confidence as they learn about finding and caring for Pok幦on.

Take your self-study English language learning and confidence to the next level with the third practice book in the visual learning series English for Everyone.Practice Book: Level 3 Intermediate will help you to solidify the skills you learn from the Course Book: Level 3 Intermediate or from your other courses or studies. Strengthen your language for topics such as skills and tasks, giving instructions, and relationships and problem solving.Grab your pen and work your way through the exercises as you cover each topic. Activities include filling in the blanks, true or false decision-making, matching the pairs, and much more. Audio material is provided at every stage through the English For Everyone website and apps to provide vital experience of spoken English and make even tricky phrases easy to understand.English for Everyone is aligned to the CEFR, the international standard for language learning, and ideal for preparation for major English-language exams including IELTS, TOEIC, and