coolant liquid

例句：

1. 1.The car's engine needs to be cooled down before starting.
   汽车发动机在启动前需要冷却。
2. 2.The refrigerant in the air conditioner is causing the unit to overheat.
   空调中的制冷剂导致机器过热。
3. 3.The coolant levels in the engine should be checked regularly to prevent damage.
   应定期检查发动机中的冷却液水平，以防止损坏。