jump the gun

释义：（赛跑时）未听发令枪就起跑，抢跑，行动过早

例句：

1、He was disqualified from the race for jumping the gun.

2、He jump the gun and open the test before the teacher say to start.

在老师说开始前，他行动过早，先翻开了试卷。

词汇解析：