You must put the sign _____ the right place.[ ]
A. in
B. on
C. with
D. for
答案:A
SAT一年可以参加几次考试?()
A.2
B.3
C.5
D.6
调节阀膜片漏气,将使调节阀的行程不够.输出压力缓慢或不正常。()