以下哪个是控制到预冷器冷却气量多少的活门?()
A.PRV
B.OPV
C.FAV
D.HPV
参考答案:C
My English teacher is really ___.She is often seen working in her office far into the night.
A.warm-hearted
B.easy-going
C.hard-working
D.self-confident
用户目录访问选项中,访问权限分______,需要分别设置。
A.文件
B.目录
C.子目录
D.以上全部