三相异步电动机的转速一般选择为()r/min。
A.3000~1500
B.3000~1000
C.2000~1500
D.1500~750
参考答案:D
被誉为“世界电影之都”的是
A.上海
B.好莱坞
C.威尼斯
D.柏林
The charity sale our school organizes every year has taught us much that we would never have _____ learned in class.
A.therefore
B.meanwhile
C.otherwise
D.instead