为了保证事故情况下发电厂厂用保安负荷的安全供电,要求设置交流保安电源的发电机组的额定容量不低于( )
A.50MW
B.100MW
C.125MW
D.200MW
参考答案:D
It must be Tom who told you about the news,________? [ ]
A. mustn't it
B. isn't it
C. isn't he
D. hasn't he
有机肥料