You scared me!  你吓到我啦！

It can't be true!  不可能是真的！

Who would have thought?  谁曾想到呢？

I could hardly believe my ears.  我简直不相信我所听到的。

Are you serious?  你是认真的吗？

Wow!  哇！

Great!  太棒了！

It's very exciting!  非常令人兴奋！

I'm too nervous to say a word.  我太紧张了，以至于说不出话来。