题目内容

与观察性研究相比较,实验性研究最基本的特点是

A. 有可重复性
B. 有人为干预措施
C. 是前瞻性研究
D. 可行性较好

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流行病学现场试验中实验组和对照组人群最大的不同点是

A. 观察指标不同
B. 目标人群不同
C. 入选标准不同
D. 干预措施不同

流行病学实验研究最常用的分析指标是

A. 发病率、流行率、有效率
B. 发病率、治愈率、保护率
C. 发病率、死亡率、有效率
D. 发病率、病死率、有效率

对于流行病学实验研究,下列哪种说法不正确

A. 设计和实验条件高,控制严,难度大
B. 样本量大,随访时间长,易失访
C. 花费人力、物力、财力,有时还可涉及医德问题
D. 其研究结果的科学价值还不如分析性研究方法

As regards the development of moral standards in the growing child, consistency is very important in parental teaching. To forbid a thing one day and excuse it the next is no foundation for morality.Also, parents should realize that “example is better than precept”. If they are not sincere and do not practice what they preach（说教）, their children may grow confused, and emotionally insecure when they grow old enough to think for themselves, and realize they have been to some extent fooled.A sudden awareness of a marked difference between their parents’ principles and their morals can be a dangerous disappointment. (1998-1-cet4)The word “precept” probably means “_____”.

A. idea
B. punishment
C. behavior
D. instruction