I was disappointed to find that they had left already.

　　我發現他們已經離開了，覺得很失望。

　　He was disappointed to see she wasn't at the party.

　　看到她沒來參加晚會，他感到很失望。

　　I'm disappointed in you ─ I really thought I could trust you!

　　你真讓我失望——我原以為可以相信你的！

　　I was disappointed by the quality of the wine.

　　這酒的質量令我失望。

　　Don't raise your hopes too high, or you may be disappointed.

　　不要希望過高，否則你可能會失望的。