Bob insisted that he ________ nothing wrong and ________ from work.

A．did; won’t be fired

B．had done; not be fired

C．should do; mustn’t be fired

D．do; shouldn’t be fired

在换热器实际的热量衡算中，单位时间内热流体放出热量（）冷流体吸收热量。

A.大于

B.小于

C.小于等于

D.等于