3 sentences for 变质 (biàn​zhì — spoil)

1. 隔夜的饭菜容易变质。

   gé​yè de fàn​cài róng​yì biàn​zhì.

   Overnight leftovers spoil easily.

   Source: Dong Chinese Dictionary

2. 我吃了点变质的鱼。

   wǒ chī le diǎn biàn​zhì de yú.

   I ate some bad fish.

   Source: OpenSubtitles

3. 由于天气炎热，剩菜已经变质了。

   yóu​yú tiān​qì yán​rè, shèng​cài yǐ​jīng biàn​zhì le.

   The leftovers have gone bad because of the heat.

   Source: Dong Chinese Dictionary