电机铭牌上功率为20KW,功率因数为0.8,则电机输出功率为()KW。
A.8
B.16
C.20
D.25
参考答案:B
Many of the students turned a deaf ear to his advice, they knew it to be valuable.
A.as if
B.now that
C.even though
D.so that
(本题4分)简述蜂蜜的卫生及管理。