要使真空沸腾式海水淡化装置凝水水位合适主要是靠控制凝水泵（）。
A.转数
B.排出阀开度
C.吸入阀开度
D.旁通阀开度
参考答案：B
He lives in a flat, _____ he can see _____ is happening in the street. [ ]
A. from whose window; all that
B. there; all
C. from its window; everything
D. where; all
Although of ______ intelligence, he speaks 4 foreign languages fluently.[ ]
A. slow
B. high
C. middle
D. average
