每当谈话转向他的过去，他就会迅速转移话题。

Whenever the conversation turned to his past, he would quickly ___change ___the ___subject.

好吧，换个话题，你决定好假期去哪里了吗？

Well, ___changing ___the ___subject, have you decided where to go for vacation yet?

看到她不舒服，我决定把话题转到更轻松的事情上。

Seeing her discomfort, I decided to ___change ___the ___subject to something lighter.