别在孩子面前说脏话。

Don't ___swear in front of the kids.

士兵们在入伍仪式上宣誓效忠国家。

The soldiers ___swore allegiance to their country during the enlistment ceremony.

我可以发誓我昨晚确实关掉了所有的灯。

I can ___swear I turned off all the lights last night.