挤岔是指列车顺向经过道岔且道岔处于四开状态，列车车轮挤过道岔使尖轨与基本轨分开。
参考答案：错
(2013·安徽安庆二模)—She looks very happy. She ________ have passed the exam.
—I guess so. It's not difficult after all.
A．should
B．must
C．could
D．might
油气回收系统保护接地电阻值不得大于4Ω。
