2 sentences

1. 夜幕降临了，城市的灯火开始闪烁。

   yè​mù jiàng​lín le, chéng​shì de dēng​huǒ kāi​shǐ shǎn​shuò.

   Night fell, and the city lights began to twinkle.

   Source: Dong Chinese Dictionary

2. 每当夜幕降临，山村就笼罩在一片寂静之中。

   měi​dāng yè​mù jiàng​lín, shān​cūn jiù lǒng​zhào zài yī piàn jì​jìng zhī​zhōng.

   Whenever night falls, the mountain village is shrouded in silence.

   Source: Dong Chinese Dictionary