She wasn't born yesterday.
她又不是三歲小孩

You can't fool her.She wasn't born yesterday.
你騙不了她，她又不是三歲孩子。
Don't try to cheat me, I wasn't born yesterday.
不要試圖欺騙我，我又不是三歲小孩。

A:Susan,do you want to drop by Tom's with me tonight?I hear he's having a party.
蘇珊，今晚你愿意和我一起去湯姆家嗎？我聽說他在舉辦晚會。
B:I wish I could.But I promised to run errands for my mom.I don't think I can get out of it.
我希望我能去。但是我已經答應了我媽媽幫她做點事。我覺得我可能推不了。
A:You could tell her something important came up.
你可以告訴她你有點著急的事情要做。
B:Like what?
比如呢？
A:You could say that an old friend turned up and that you wanted to see her.
你可以說，來了一個好朋友，你想見她。
B:I don't think she'll believe such excuses.She wasn't born yesterday,you know.Maybe I can come later on.
我覺得她不會相信這種借口。她又不是小孩子。沒準我可以晚點去。