二十五岁初产妇，妊娠38周，规律宫缩12小时，宫缩间隔4分钟，持续40秒，宫口3cm，胎心基线119次／分。此时胎膜自破，为黄色质稀，判断为羊水Ⅰ度。

胎心监护显示频繁早期减速，宫口4cm，先露0位，接下来的处理是（）

A.继续严密观察

B.胎吸助产

C.产钳助产

D.立即剖宫产

E.静脉滴注缩宫素，促进产程进展

By the time Jack returned home from England, his son ________ from college.[ ]

A. graduated  

B. has graduated

C. had been graduating  

D. had graduated