4 sentences

1. 这两条直线是平行的。

   zhè liǎng tiáo zhí​xiàn shì píng​xíng de.

   These two straight lines are parallel.

   Source: Dong Chinese Dictionary

2. 这部电影由两条平行的线索交织而成。

   zhè bù diàn​yǐng yóu liǎng tiáo píng​xíng de xiàn​suǒ jiāo​zhī ér chéng.

   The movie is woven from two parallel storylines.

   Source: Dong Chinese Dictionary

3. 两项任务在平行进行。

   liǎng xiàng rèn​wu zài píng​xíng jìn​xíng.

   The two tasks are being carried out in parallel.

   Source: Dong Chinese Dictionary

4. 他们两个部门是平行关系。

   tā​men liǎng gè bù​mén shì píng​xíng guān​xi.

   The relationship between these two departments is parallel.

   Source: Dong Chinese Dictionary