一台并网运行的同步发电机,原动机输入功率不变,增加励磁电流,则功率角()。
A.变大
B.不变
C.变小
参考答案:C
With everything needed_____, Mrs. Jackson went to the supermarket after work in a hurry.
A.buying
B.to buy
C.bought
D.Buy
滚动轴承在装配前测出的径向间隙,称为()。
A、工作游隙;
B、原始游隙;
C、配合游隙;
D、空载游隙。