当导线和磁场发生相对运动时,在导线中产生感应电动势的方向可用()确定。()
A、右手螺旋法则
B、右手定则
C、左手定则
D、电磁感应定律
参考答案:B
我国国务院各部、委的设立、撤销或合并,其决定权在于()。
A.全国人民代表大会
B.国务院 * *
C.国家 * *
D.国务院全体会议
After years of overwork, my father’s health ____ and he had to retire from business.
A.broke out.
B.broke up.
C.broke down.
D.broke off.