根据句意填写适当的单词 。

1. I spcnt a long summer __________.

2. A lot of __________ visit our city every year.

3. I think going  __________ in the forest is a good activity.    ,

4. I hope I can __________ all my problem after I come back from my trip.

5. Julia is going to have a long vacation in a beautiful __________ because it is far from the city.

下列关于肺泡表面活性物质生理作用的叙述，哪一项是错误的

A．稳定肺泡内压

B．降低肺泡表面张力

C．增加肺的回缩力

D．维持肺泡于适当的扩张状态

E．阻止血管内水分滤人肺泡