如果一项政策预期的效果较小,应采用的方法是()。
A.非随机试验法
B.抽样调查法
C.问卷调查法
D.随机试验法
参考答案:D
Generous public funding of basic science would () considerable benefits for the country's health, wealth and security.
A.result from
B.settle down
C.lie in
D.lead to
青少年期后逐渐萎缩()
A.骨髓
B.胸腺
C.淋巴结
D.脾
E.黏膜相关淋巴结组织