【英语时差8,16】恒温器的工作原理2

 In a thermostat¹, the bimetallic coil is fastened firmly at one end. The other end is free to move. Its motion, as the temperature changes, can be used to control your furnace. For example, if the coil tightens² as it cools, the free end can curl toward a metal contact that starts the furnace. As the air heats up and the coil loosens, the free end curls away from the contact and the furnace shuts off. When you adjust the thermostat you move the contact. When the contact is closer to the end of the coil, it will take a smaller drop in temperature to activate³ the furnace and your house will be warmer. Sliding the contact away will keep your house cooler.

1 thermostat   

n.恒温器

参考例句：

• The thermostat is connected by a link to the carburetor.恒温控制器是由一根连杆与汽化器相连的。
• The temperature is controlled by electronic thermostat with high accuracy.电子恒温器，准确性高。

2 tightens   

收紧( tighten的第三人称单数 )； （使）变紧； （使）绷紧； 加紧

参考例句：

• One set of provisions tightens emission standards. 一套使排放标准更加严格的规定。 来自英汉非文学 - 环境法 - 环境法
• Requires no special tools or fittings; hand tightens to relief valve outlet. 不需要专用工具或管件；用手将其紧固到安全阀上即可。

3 activate   

vt.使活动起来，使开始起作用

参考例句：

• We must activate the youth to study.我们要激励青年去学习。
• These push buttons can activate the elevator.这些按钮能启动电梯。