题目

They were so ________________ to see some kangaroos jumping outside the car. A . surprise B . surprising C . surprised D . a surprise 答案：C如右图所示，导线ab左右摆动的过程中，电流表指针会发生偏转．这个现象所反映的物理原理，在下列电器设备中得到应用的是A.电动机B.发电机C.电磁起重机D.电磁续电器