not do a thing

例句：

1. 1.I'm not doing a thing about it.
   我对此什么都不做。
2. 2. She didn't do a thing to help him.
   她没有做任何帮助他的事。
3. 3. If you don't do a thing about it, you'll regret it later.
   如果你对此不采取任何行动，你会后悔的。