"Don't fall for it!"Which situation should I use this sentence?It's better to give an example.

问题描述:

"Don't fall for it!"Which situation should I use this sentence?
It's better to give an example.

fall for:
vt.信以为真(对...倾倒)
例句与用法:
1.The salesman said the car was in good condition,and I was foolish enough to fall for it.
推销员说这辆汽车状况良好,而我那麽傻竟然信以为真.
2.They met,fell for each other and got married six weeks later.
他们俩一见倾心,六个星期后就结了婚.
3.He must have been pretty gullible to fall for that old trick.
他准是有点儿傻,才落入那惯用的圈套.
4.Did she fall for the suggestion?
她喜欢这个提议吗?