3 sentences

1. 他脸上带着一丝忧郁的神情。

   tā liǎn shàng dài zhe yī sī yōu​yù de shén​qíng.

   There was a touch of melancholy in his expression.

   Source: Dong Chinese Dictionary

2. 他那双深陷的眼睛显得忧郁而深邃。

   tā nà shuāng shēn​xiàn de yǎn​jing xiǎn​de yōu​yù ér shēn​suì.

   His sunken eyes appeared melancholy and profound.

   Source: Dong Chinese Dictionary

3. 他深深地唉了一口气，显得非常忧郁。

   tā shēn​shēn de āi le yī kǒu qì, xiǎn​de fēi​cháng yōu​yù.

   He let out a deep sigh and looked very depressed.

   Source: Dong Chinese Dictionary