你現在退學無異自斷後路。
If you drop out of school now, you’ll be burning your bridges behind you.
2.自斷生路 cut one’s throat
我們又不是傻瓜，要是我們捕太多鯨魚，我們必定會自斷生路。
We’re not stupid. If we catch too many whales, we will cut our own throats.
3自掘墳墓 drive a nail into one’s coffin (idiom)
你抽煙就是自掘墳墓。
By smoking you are just driving nails into your coffin.
4 自取滅亡
(1) sign one’s own death warrant (idiom)
如果你繼續這樣搞下去，遲早會自取滅亡。
If you continue to do it that way, sooner or later you’ll sign your own death warrant.
(2為非作歹的人遲早會自取滅亡。
Evildoers are doomed to court their own ruin.
