We had to _____the sports meet because of the heavy rain.

A．put away

B．put up

C．put off

D．put on

劳兰C主台故障信号是用（）来表示的。

A.另增设一个可左右移动的脉冲信号

B.另增设一个可闪光的脉冲信号

C.主台的识别脉冲闪烁

D.主台脉冲组重复少发一个脉冲