初产妇，25岁。孕39周，产妇烦躁不安、持续腹痛、拒按，子宫收缩出现子宫痉挛性狭窄环，常见于（）。

A.羊水过多

B.双胎

C.巨大儿

D.胎盘早期剥离

E.先兆子宫破裂

— Hi, Johnson, any idea where Susan is?    

— It's class time, so she          in the classroom now.  

A. can be

B. must have been

C. might have been

D. should be