高速旋杯式自动静电喷涂机涂料液滴雾化直径可达到()um。
A.20~30
B.30~50
C.50~100
D.100~200
参考答案:C
He speaks English as fluently as if he__________an Englishman.
A.were
B.had been
C.is
D.has been
网络操作系统能否安装在PC机上?