我们遇到了一个意外的情况。

Wǒmen yù dào le yīgè yìwài de qíngkuàng.

We encountered an unexpected situation.

他的成功完全出乎意料，让人意外。

Tā de chénggōng wánquán chūhū yìliào, ràng rén yìwài.

His success came as a complete surprise.

在旅行中，他们发生了一次意外。

Zài lǚxíng zhōng, tāmen fāshēngle yīcì yìwài.

They had an accident during the trip.