VV230/180－2型空气压缩机共有（）个压缩气缸。
A.1
B.2
C.3
D.4
参考答案：D
Internet主要功能包括远程登录、文件传输、信息查询、电子商务。
Categories of risk response are（）
A.Identification, quantification, response development, and response control
B.Marketing, technical, financial, and human
C.Avoidance, retention, control, and deflection
D.Avoidance, mitigation, acceptance, and transferring
