Once germs are inside your body, your immune(免疫的)system tries to protect you. It looks for and destroys germs. How does it do that? Special cells patrol your body. Some of these cells actually eat germs! Other cells make antibodies. An antibody sticks to a germ. There is a different antibody for each kind of germ. Some antibodies keep germs from making you sick. Others help your body find and kill germs. After a germ is destroyed, the antibodies stay in your body. They protect you if the same kind of germ comes back. That way you will not get the same illness twice.
You can keep your body healthy by eating a nutritious(有营养的)diet to make your immune system strong. You can also help your immune system fight germs by getting vaccinated(接种).Vaccines are medicines. They contain germs that have been killed or weakened. The dead germs can’t make you
your antibodies attack it.
16. Viruses can only live inside people or animals.
【答案】:B
17. All bacteria cause illnesses.
【答案】:B
18. Washing your skin can prevent some illnesses.
【答案】:A
19. Germs can enter the body through the eyes.