【单选题】关于直流电动机的感应电动势, ,下列说法正确的是( )
C.
在静态和动态下,感应电动势与转速均成正比关系
D.
在静态和动态下,因为其他因素的影响,感应电动势与转速均不成正比关系
【单选题】导游员需要做到爱护公物,助人为乐,保护环境,遵纪守法,这体现了导游员的意识。
【多选题】下面绝缘安全工具试验周期为一年的是( )
【单选题】Rosita is said _____ in Japan, but I don’t know what city she studied in.
【单选题】Tea ceremony, though it is now most popular in Japan, is said_______ in ancient China.
A.
to have been originated
C.
to have been originating
【单选题】The climate here is often said to be similar to ______.
【单选题】关于电压,下列说法不正确的是
C.
电源使正电荷聚集在电源负极,使负电荷聚集在正极,从而产生电压