It was sad to see them go.

　　看著(zhù)他們離去，真讓人難過(guò)。

　　You'd have to be sad to wear a shirt like that.

　　你穿著(zhù)那樣的襯衣顯得老氣。

　　I was very sad indeed to hear of your father's death.

　　聽(tīng)到令尊大人去世，我感到非常難過(guò)。

　　We are very sad to hear that you are leaving.

　　聽(tīng)說(shuō)你要走了，我們十分難過(guò)。

　　Her moods kept changing ─ now happy, now sad.

　　她的情緒總是變幻不定——時(shí)而歡喜，時(shí)而憂(yōu)傷。