智能温控器采用闭环系统，根据室内温度自动调节暖气输出。

The smart thermostat uses a ___closed-loop system to automatically adjust heating output based on room temperature.

这台空调采用闭环控制系统，能根据室温自动调节制冷强度。

The air conditioner uses a ___closed-loop system to automatically adjust cooling based on room temperature.