某台交流电动机铭牌功率为4.5KW，其含义表示（）。
A.无功功率
B.有功功率
C.视在功率
D.电源功率
参考答案：B
—It' s sunny today, Daddy, How about going swimming with me?
—_______. Let's ask your mommy to go with us. [ ]
A. Don't worry
B. Never mind
C. Not at all
D. Good idea
开发利润测算只有在传统方法中才需要。（）
