to give careful attention to something, especially something that someone says

He hangs on her every word as if she were some sort of goddess. 他全神贯注地听她讲每一句话，就好像她是位女神似的。

to depend on something

The safety of air travel hangs partly on the thoroughness of baggage checking. 乘飞机旅行的安全性在一定程度上依赖于对行李细致彻底的检查。