---The terrible earthquake brought about a loss of $15 million to this island country.

---___.

A．Certainly

B．I agree with you

C．It’s OK

D．That’s the case

仔细分析电路原理，判断故障所在。要测试必要点的( )，多做一些试验，以便于分析。

A．电流或波形

B．电压或波形

C．电压或电流

D．电阻或电流