每班使用前，必须对煤电钻综合保护装置进行1次（）试验。
A、合闸
B、跳闸
C、运行
参考答案：B
He ________ me to come to my birthday party, but until it was over he didn’t appear at all.
A．asked
B．told
C．agreed
D．promised
配子的运行
