I'm speechless to know that so many people are behind me.

知道这么多人跟在我后面，我说不出话来。

I'm speechless, Scott said. I don't know how to even explain it.

我说不出话来，斯科特说。 我甚至不知道该怎么解释。

I don't know what to say. I'm speechless.

我不知该说些什么。我无话可说。