班级授课的特殊形式是( )
A.分组教学
B.个别教学
C.复式教学
D.现场教学
参考答案:C
George said that he would come to school to see me the next day, but he ______.[ ]
A. wouldn't
B. didn't
C. hasn't
D. hadn't
直流并励电动机采用能耗制动时,切断电枢电源,同时电枢与电阻接通,并(),产生的电磁转矩方向与电枢转动方向相反,使电动机迅速制动。
A、增大励磁电流
B、减小励磁电流
C、保持励磁电流不变
D、使励磁电流为零