呃，我忘记把钥匙放哪了。

___Uh, I forgot where I put the keys.

我想吃...呃...披萨还是汉堡呢？

I want to eat... ___uh... pizza or burger?

呃，让我想想该怎么回答这个问题。

___Uh, let me think about how to answer this question.