change the subject|changed the subject|changing the subject

当谈话变得太私人时，她决定改变话题。

She decided to ___change ___the ___subject when the conversation became too personal.

我试图解释情况，但他只是改变了话题。

I'd tried to explain the situation, but he just ___changed ___the ___subject.

好吧，换个话题，我不小心打碎了你漂亮的花瓶。

Well, ___changing ___the ___subject, I accidentally broke your beautiful vase.