凝汽器内的排汽温度比它对应压力下的温度为低，说明（）。
A.排汽量太少
B.冷却水温太低
C.有空气漏入
D.有氮气漏入
参考答案：C
He knew the problem was serious and promised to look into it _____ he reached office.
A．at that moment
B．for that moment
C．immediately
D．soon
发动机润滑油的牌号为CE15W/40是什么意思？
