问题 单项选择题

下列哪项是病例对照研究的优点()。

A.可用于研究少见病的病因

B.在选择出暴露因素后,可研究多种疾病的结局

C.可减少研究对象对回忆的依赖性

D.有可能确立该病的真实发病率

E.估计对危险因素的暴露情况时,很少或没有偏倚

答案

参考答案:A

完形填空

Breakfast is very important. It is one of the most important(最重要的) 小题1: of the day. To keep healthy, everyone should 小题2:  a good breakfast.小题3:  the right food is necessary for good health. We may have eggs, bread, milk  小题4: breakfast.

Many students go to school without breakfast 小题5: they get up late or their parents don’t cook for them. It’s  小题6: for their health.

 小题7:2 breakfast children may not grow fast and may not study and play very well at school. They may 小题8: . And when they’re ill, they will 小题9: a long time in recovering (恢复).

I think everyone should have some good   小题10: habits. It is necessary.

小题11:A. meal               B. meals             C. dinner

小题12:A.to have             B. have              C. has

小题13:A.Eating              B. Eats              C. Eat

小题14:A.in                  B. on               C. for

小题15:A.because             B. so                C. but

小题16:A.good               B .bad               C. better

小题17:A.Without             B. With             C. Not have

小题18:A.ill                  B .are ill            C .be ill

小题19:A.spend              B. take              C .make

小题20:A.health               B .healthy            C. bad

单项选择题