浊度计中使用的光电检测元件类型有（）。
A、光电管
B、光电倍增管
C、光敏电阻
D、光电池
参考答案：A, B, C, D
The rate of unemployment in America after the worldwide economic crisis may be ______ reported earlier.
A．as twice high as
B．twice as high as
C．as high twice as
D．as high as twice
规章制度管理
