我们终于下定决心要买房子了。

We're finally going to ___take ___the ___plunge and buy a house.

我决定采取行动，跟着他去解开谜团。

I decided to ___take ___the ___plunge and follow him to solve the mystery.

经过多年考虑，她终于下定决心转行了。

After years of contemplation, she finally ___took ___the ___plunge and changed her career.