一般末经补偿的电压互感器的比差和角差，（）。
A、比差为正，角差为正
B、比差为负，角差为正
C、比差为负，角差为负
D、比差为正，角差为负
参考答案：B
--- Don’t you think it necessary that he __________ to Miami but to New York?
--- I agree, but the problem is __________ he has refused to.
A．will not be sent; that
B．not be sent; that
C．should not be sent; what
D．should not send; what
使用NDB台导航时，必须作到（）
A.正确调谐电台
B.监听识别信号
C.正确调谐电台和监听识别信号
