测定系统真空度的一般仪表是()
A、正压压力表
B、负压压力表
C、U型压力计
D、微压计
参考答案:B
He's got himself into a dangerous situation he is likely to be accused of meeting someone. [ ]
A. where
B. which
C. while
D. why
. --- Is this park you’ve visited recently?
--- Yes, it's the most beautiful one I’ve ever visited before.
A.the one
B.that
C.which
D.the one which