问题 单项选择题

移民流行病学是对移民人群的疾病分布进行研究,来探讨病因。若移民中某病的发病率及死亡率与原居住地人群的发病率或死亡率不同,而与移民地当地居民人群的发病率及死亡率接近,则引起发病率及死亡率差别的主要原因是

A.遗传因素

B.环境因素

C.遗传和环境交互作用

D.很难判断

E.以上均不正确

答案

参考答案:B

阅读理解

阅读理解。

     Everyone may play a joke on others on April Fool's Day. And my father did last April Fool's Day.

     It was Sunday and we were all sitting at the table when father suddenly smiled and said to us, "Oh, dear,

I forgot to tell you the good news. There's a letter from granny. She is coming to see us this afternoon. I'm

going to meet her at the station." With these words he went out.

     How happy we were! We hadn't seen granny for nearly a year and we missed her very much. After lunch

my mother and I went shopping. We bought a lot of food that granny liked. My sister cleaned the house. It

was four o'clock when we finished and we sat around the table, waiting for granny. At last the door opened

and came in my father, alone.

     "Where's granny?" We asked.

     Father laughed and said, "April Fools! Today is April 1st, April Fool's Day."

     We were disappointed after we heard this, but we all laughed.

Notes: 1. play a joke on 开……玩笑2. April Fool's Day 愚人节

          3. station n. 车站 4. with these words 说完这些话

根据短文回答问题:

1. When did people like to play jokes?

    _______________________________________________

2. Where did my father meet my granny?

    _______________________________________________

3. Why did we buy a lot of food?

    _______________________________________________

4. Who came in when the door opened?

    _______________________________________________

5. Did my granny come? 

   ________________________________________________

单项选择题