读短文，选择。   

     In winter some people get sick in the cold weather. If you don't wear enough clothes, you will have

a cold.  How does it feel if you have a cold?You will feel very tired. Your head may hurt badly. Your

temperature (体温) will be higher. You may also have a fever. But don't worry too much, go to see a

doctor first. Take some medicine and stay in bed for a few days. And drink lots of hot water. Then

you will get well soon.

1. People feel sick in winter because it's __ __.             

A. warm    

B. cold

2. If you have a cold you will feel          .              

A. tired    

B. happy

3. If your temperature is higher than 37℃, you will ____.          

A. have a cold    

B. have a fever

4. If you are sick, you must ____.         

A. see a doctor    

B. go to school

5. ____ is good for you when you're sick.          

A. Drinking hot water    

B. Drinking cold water

影子是由于光的______形成的，海市蜃楼是光线经不均匀的大气时发生了______现象形成的．