Their answers are exactly the same. One of them ___ from the other.

A．must copy

B．must have copied

C．should copy

D．should have copied

关于妊娠期消化系统变化，错误的是（）

A.妊娠晚期，胃向左上方膈肌顶部推移

B.胃肠道平滑肌受胎盘分泌的孕酮的影响引起张力降低

C.贲门括约肌松弛使胃内容物容易返流

D.肠道张力增高，胃排空时间缩短

E.胃肠道张力降低，蠕动减弱，胃排空时间延长