三相异步电动机的转速决定于()。
A.电压
B.电流
C.电动机大小
D.旋转磁场转速
参考答案:D
I have _____ a member of the music club for many years.
A. been B. became C. joined
男性,12岁。智力低下、言语障碍11年。CT检查如图所示,请根据CT图像给出正确诊断()
A.蛛网膜囊肿
B.脑裂畸形
C.Dandy-wallker综合征
D.囊性胶质瘤
E.左侧侧脑室室间孔闭锁或狭窄