Jerry has promised to keep the secret, so he won't tell anyone ________ asked to.

A．until

B．now that

C．unless

D．even though

熔断器更换完后，在合闸送电时，应检查线路有无其他作业，（）应进行试送电。

A、拉闸时

B、合闸时

C、更换时

D、选用时