发动机驱动泵何时处于释压模式()
A.发动机泵按钮松出后;
B.只要发动机运转,不可能处于释压模式;
C.发生液压渗漏时。
参考答案:A
He was told that it would be at least three more months______he could recover and return to work.
A.when
B.before
C.since
D.that
含碳量在0.04-2.3之间的铁碳合金叫()。
A.钢
B.铁
C.纯铁
D.无法确定