L-12：live by/on one's wits 混日子

A:Do you know that Jack got divorced last month?

A：你知道吗，杰克上个月离婚了。

B:For what reason?

B：为什么?

A:Jack always lives by his wits and he cannot support his family.

A：他一直靠耍小聪明混日子，根本不能养活自己的家庭。

B:He'd better make a change.

B：他是应该改改了。