卧室里的恒温器会在温度低于20度时自动开启暖气。

The ___thermostat in the bedroom turns on the heater when the temperature drops below 20 degrees.

空调的恒温器坏了，房间里一会儿冷一会儿热。

The air conditioner's ___thermostat is broken, making the room temperature fluctuate.