警方用枪封锁了那栋大楼的出口。

The police covered the exits to the building.

《牛津词典》

一个男人用枪指着他们，扣动了扳机。

A man pointed a gun at them and pulled the trigger.

《柯林斯英汉双解大词典》

他一边逃跑，一边用枪对准追他的警察。

He fled, pointing the gun at officers as they chased him.

《柯林斯英汉双解大词典》

There'd be certain activities perhaps, for example putting a gun to your head, that would put an end to your life.

也许会有某些特定的活动，比如用枪指着你的头，会结束你的生命。

耶鲁公开课 - 死亡课程节选

because you're thinking the guy might be trying to steal your car, put you at gunpoint, hijack you,

因为你会想这个人可能是想偷你的车或用枪威胁你，劫持你，

大城市是否危险？ - SpeakingMax英语口语达人

And one of the brothers points a gun at the police officer.

兄弟中的一个用枪指着警察

耶鲁公开课 - 心理学导论课程节选