A business letter should be written in a formal style _____ in a personal one.[ ]

A. rather than

B. other than

C. beater than

D. less than

带负荷合隔离开关时，发现合错，应（）。

A、不准直接将隔离开关再拉开

B、在刀片刚接近固定触头，发生电弧时，应立即拉开

C、在刀片刚接近固定触头，未发生电弧，这时应立即拉开

D、准许直接将隔离开关再拉开