1·It was a really bad mistake.
这是一个非常严重的错误。
2·The engagement was a bad mistake.
这婚约是一项大错。
—— 《牛津词典》
3·Someone just make a bad mistake!
有人犯了一个很严重的错误！
4·I'm afraid he's made a bad mistake.
我恐怕他犯了一个严重的错误。
5·That was a bad mistake.
那是个严重的错误。
6·That was a bad mistake.
那是一个大错。
7·That was a bad mistake.
那是一项大错。
8·You made a bad mistake on that jump shot.
那次跳投你犯了一个很大的错误。
9·Mr Obama seems also to have made another bad mistake.
奥巴马先生似乎还犯下了另外一个错误。
10·I made a bad mistake in spending all the money at once.
我犯了个严重错误，把所有的钱一下子都花光了。