正压式空气呼吸器主要有（）部件总成。
A.气瓶总成
B.减压器总成
C.供气阀总成
D.面罩总成
E.背架总成
参考答案：A, B, C, D, E
She won the first prize；though none of us it.
A．expected
B．had expected
C．was expected
D．would expect
简述企业文化的功能。
