—Mum, where can we put our new TV set?

—Look, we can remove the picture in order to make some ________ for it.

A．area

B．room

C．wall

D．place

下列几种真空装置中，（）产生的真空度最易受季节影响。

A.蒸汽喷射泵

B.水力喷射泵

C.干式真空泵

D.水环真空泵