根据有关规定，开放式基金的募集期限为自基金份额发售之日起计算不得超过( )个月。A．

用所给词的适当形式填空。

1. They hope _____ (visit) China again.

2. We won't begin the meeting until he _____ (come).

3. I had some problems _____ (work) out the math problem.

4. Thanks a lot for _____ (invite) me to your birthday party.

5. Did you watch those boys _____ (play) soccer yesterday afternoon?

可出现平均肺动脉压降低的是（）

A.肺血管阻力升高

B.二尖瓣狭窄

C.肺动脉狭窄

D.左心功能不全

E.肺血流量增加

I really wonder__________ he has posted me many parcels___________ we didn’t work together.

A．that; before

B．which; since

C．X; when

D．that; since

全球鹰是美国生产的无人驾驶侦察机。

对飞机上面积很小的空速管、静压孔和失速传感器叶片等探头，除冰方式通常采用：（）.

A.气热防冰

B.电热防冰

C.化学防冰

D.气动防冰