冷热水管道安装时，热水管在（），冷水管在（），冷水龙头在（），热水龙头在（）。
参考答案：上面、下面、右边、左边
His efforts to raise money for his program were _______ because no one showed any intention to take a cent out of their pockets.
A．in place
B．in vain
C．in effect
D．in sight
加油站卸油时，（）必须在现场监卸。
A.罐车司机
B.安全员
C.记账员
D.加油员
