24岁初产妇，规律宫缩12小时，连续观察2小时，宫口由6cm开大至7cm，胎头S，胎心率140次／分。本例正确处置应是（）

A.严密观察产程进展

B.肌内注射哌替啶100mg

C.静脉滴注缩宫素

D.立即行人工破膜

E.立即行剖宫产术

—When will you come to Daqing?

—I will call you ________ I arrive. [ ]

A. till

B. while

C. as quickly as

D. as soon as