检查车辆时，请先摆放好三角警示牌。

Before checking the vehicle, set up a ___warning ___triangle first.

这个标志表示警告

This sign is a ___warning.

医生给了他一个警告，如果继续吸烟会有严重的健康问题。

The doctor gave him a ___warning that continuing to smoke could lead to serious health problems.

老师给了我们一个警告，不要在教室跑跳。

The teacher gave us a ___warning not to run or jump in the classroom.