4 sentences

1. 水在摄氏零度时结冰。

   shuǐ zài Shè​shì líng dù shí jié​bīng.

   Water freezes at zero degrees Celsius.

   Source: Tatoeba

2. 赤道是零度纬线。

   chì​dào shì líng dù wěi xiàn.

   The equator is the zero-degree line of latitude.

   Source: Dong Chinese Dictionary

3. 今天的气温降到了零度以下。

   jīn​tiān de qì​wēn jiàng​dào le líng dù yǐ​xià.

   Today's temperature dropped below zero.

   Source: Dong Chinese Dictionary

4. 气温低于零度。

   qì​wēn dī​yú líng dù.

   The temperature is below freezing.

   Source: Dong Chinese Dictionary