空载特性是指无负荷时发电机端电压与()的变化规律。
参考答案:转速
—Are you pleased with what he has done?
—Not at all. It couldn’t be _______. Why didn’t he put more effort into his work?
A.any worse
B.much better
C.so bad
D.the best
简述市场规范管理主要职责?