题目

电动机的电枢阻值为R，电动机正常工作时，两端的电压为U，通过的电流为I，工作时间为t，下列说法中正确的是(        ).(A)电动机消耗的电能为UIt                (B)电动机消耗的电能为I2Rt(C)电动机线圈产生的热量为I2Rt        (D)电动机线圈产生的热量为U2t/R 答案：答案:AC_____ for the timely investment from the general public, our company would not be so thriving(兴旺的) as it is.  A. Had it not been      B. Were it not     C. Be it not    D. Should it not be