Have you ever been ill? When you are ill，you feel unhappy because your body be comes hot，and there are pains all over your body．You don’t want to work, you stay in bed and feel very sad．

    What makes us ill? It is germs（细菌）．Germs are everywhere．They are too small and you can’t find them with your eyes，but you can see them with a microscope（显微镜）．They are very small and there could be hundreds of them on a very small thing．

  Germs are always found in dirty water．When we look at dirty water under the microscope，we shall see them in it．So your father and mother will not let you drink dirty water．

    Germs aren’t found only in water．They are found in air and dust（灰尘）．If you cut your finger，if some of the dust from the floor goes into the cut，some of the germs will go into your finger．Your finger will become big and red，and you will have much pain in it Sometimes the germs will go into all of your body，and you will have pain every where．

    根据短文内容，回答下列问题。

1．Are germs only in dirty water?

2．Why can’t we see germs with our eyes?

3．How do you feel when you are ill?

4．There are some germs on your finger if it is cut，aren’t there?

5．What does the passage mainly tell us?