WHO规定正常生育者精子活动力在射精后60min内,a级精子应
A.>5%
B.>15%
C.>25%
D.>45%
E.>50%
参考答案:C
(09年天津卷)巴以矛盾导致中东地区长期动荡,引起国际社会广泛关注。当前在联合国框架下解决巴以矛盾的基本原则是
A.以土地换和平
B.按宗教地区分治
C.大国协助解决
D.联合国托管耶路撒冷
After two hours they stopped ____a rest. [ ]
A. having
B. have
C. to have
D. had