对带有（）及其以上电压的信号设备进行作业时，一般应切断电源或双人作业。

A、36V

B、40V

C、110V

D、220V

My suggestion is ______ we should have mercy ______ these homeless children and offer them some help.

A．that; on


B．what; to
C．which; for


D．that; for