回归大海的小鱼 The Little Fish Returning to the Sea.

1. 暗淡 (Àn Dàn): gloomy，describes a situation or atmosphere that lacks brightness, often appearing dull or subdued.

   - Example: 

Yǔ hòu tiānkōng xiǎnde àndàn, yángguāng bèi yún céng zhēdǎng.雨后天空显得暗淡，阳光被云层遮挡。

     - (The sky appears dim after the rain, with sunlight blocked by clouds.)

2. 原地打转 (Yuándì Dǎ Zhuǎn):

   - Translation: Spin one's wheels

   - Explanation: Refers to staying in the same place without making progress, often used to describe futile or unproductive efforts.

   - Example: 

Tā zài gōngzuò shàng gǎndào yuándì dǎ zhuǎn, xūyào xīn de tiǎozhàn.他在工作上感到原地打转，需要新的挑战。

     - (He feels like he's spinning his wheels at work and needs new challenges.)

3. 索性 (Suǒ Xìng): Might as well, expresses the idea of choosing a particular course of action when faced with difficulties or uncertainties.

   - Example: 

Shìqing yǐjīng zhèyàng le, suǒxìng fàngxià, chóngxīn kāishǐ ba. 事情已经这样了，索性放下，重新开始吧。

     - (Since things are already like this, might as well let go and start anew.)

4. 闷闷不乐 (Mèn Mèn Bù Lè):  Moping; in low spirits, describes a state of being unhappy, dull, or downcast, often characterized by a lack of enthusiasm.

   - Example: 

Zuìjìn tā yīzhí mèn mèn bù lè, hǎoxiàng yǒu shénme fánxīn shì.

最近他一直闷闷不乐，好像有什么烦心事。

     - (He has been moping lately, as if something is bothering him.)