活塞式空压机一级气压（）时报警并停机。
A.≥0.15MPa
B.≥0.2MPa
C.≥0.23MPa
D.≥0.25MPa
参考答案：B
_____ I know the money is safe, I shall not worry about it. [ ]
A. Even though
B. Unless
C. As long as
D. While
