水泵停泵司机应怎样操作（）
A、关闭配水闸阀
B、关闭真空表和压力表旋钮
C、停泵按钮
参考答案：A, B, C
John was ________ to learn the news that he was rejected by the committee.[ ]
A. cast down
B. cast off
C. cast about
D. cast away
期权的碟式套利策略是如何构造的？用图表作出套利损益图。
