国产浅冷装置天然气压缩机停机后,应打开(),排净系统中的污油污水
A、入口放空阀
B、排污阀
C、二段出口阀
D、出口放空阀
参考答案:B
It doesn't matter if they want to come to your party, ________?[ ]
A. doesn't it
B. does it
C. don't they
D. do they
E—mail地址的格式为()
A.用户名@邮件主机域名
B.@用户名邮件主机域名
C.用户名邮件主机域名@
D.用户名@域名邮件主机