遗传筛查的手段应包括（）.
A.羊膜腔穿刺行羊水检查
B.绒毛活检
C.羊膜腔胎儿造影
D.CT
E.胎儿镜检查
参考答案：A, B, C, E
It’s not ____books you read but the way___ you read them that decides how successfully you gain knowledge .
A．a number of ; in which
B．the number of ; /
C．a good many ; which
D．quite a few ; in which
确定公文成文日期的依据有( )。
A．领导人签发日期
B．印发日期
C．会议通过日期
D．审稿日期
