壳管式冷凝器冷却水在（）部位流动
A.左端盖
B.右端盖
C.冷却管内
D.冷却管外
参考答案：C
Let's . [ ]
A. run
B. runs
C. running
Astronauts in a spaceship have to _______weightless conditions _______are quite different from ______are on the earth.
A．do with; which; those
B．deal with; that; that
C．solve; that; what
D．face; which; these
