盐酸维拉帕米()
A.甲硝唑
B.枸橼酸乙胺嗪
C.枸橼酸哌嗪
D.奎宁
E.吡喹酮
参考答案:D
_____ to the party, Joan was greatly hurt.
A.Having not been invited.
B.Having not invited
C.Not having been invited
D.Not having invited
在流行病学实验研究中,研究对象的随机分组是为了保证()
A.实验组和对照组人数相同
B.提高研究对象的依从性
C.实验组和对照组都受益
D.平衡实验组和对照组各种混杂因素
E.实验设计和实施简便易行