妊娠时，B超检查探及胎动、胎心搏动是在（）
A.妊娠6周
B.妊娠40天
C.妊娠35天
D.妊娠2月
E.妊娠3月后
参考答案：E
4. Mr. Smith ______ that he had made a mistake and that he had corrected it.
A．accepted
B．admitted
C．talked
D．Promised
如何看待进入壁垒的福利效应？
