当某种原因造成肺泡表面活性物质减少时，可能会出现下面哪种现象（）

A.肺泡扩张

B.肺泡水肿

C.肺的顺应性变大

D.弹性阻力减小

E.肺气肿

The phrase when built in the certificate of vessel’s nationality definitely means（）.

A.when was your vessel built

B.at what time is your vessel building

C.when is your vessel built

D.at what time you built your vessel