3 sentences

1. 由于停电，走廊里的灯光变得非常暗。

   yóu​yú tíng​diàn, zǒu​láng lǐ de dēng​guāng biàn de fēi​cháng àn.

   The light in the corridor became very dim due to the power outage.

   Source: Dong Chinese Dictionary

2. 她看客人已经走远，便回身把大门暗上。

   tā kàn kè​rén yǐ​jīng zǒu​yuǎn, biàn huí​shēn bǎ dà​mén àn shàng.

   Seeing that the guests had gone far away, she turned around and quietly closed the gate.

   Source: Dong Chinese Dictionary

3. 他在大是大非面前显得非常暗，甚至不分好坏。

   tā zài dà​shì​dà​fēi miàn​qián xiǎn​de fēi​cháng àn, shèn​zhì bù fēn hǎo​huài.

   He seemed very muddled regarding major issues of right and wrong, even failing to distinguish between good and bad.

   Source: Dong Chinese Dictionary