当直流电机带上负载后，电机的气隙磁场由主磁场和电枢两个磁场共同决定。
参考答案：对
----Is that the small town you often refer to?
----Right, just the one ______ you know I used to work for years.
A．which
B．where
C．that
D．what
中药保护期限为10年的品种，其保护的级别为几级（）
A.1
B.2
C.3
D.4
E.5
