流行病学的主要研究对象（）
A.病人
B.健康人
C.人群
D.患病动物
E.非患病动物
参考答案：C
Some people worry they are heavier than their friends, so they _____ breakfast. This is a bad idea. [ ]
A. don't eat
B. haven't eaten
C. hadn't eaten
D. didn't eat
在WISC-CR中，主要评量注意力与短时记忆的能力的分测验为（）。
A.常识
B.类同
C.译码
D.背数
