Looks at the three types of germs, bacteria, viruses, and protists, that can cause illness in the body and describes how the immune system, made up of skin, white blood cells, and antibodies, overcome
Explains what the center of the earth is made of and describes what the reader would need to dig to the core, including a special outfit and ship to survive the heat and pressure.
Explains what the center of the earth is made of and describes what the reader would need to dig to the core, including a special outfit and ship to survive the heat and pressure.