In the evening, Xiaolan remembered that the homework assigned by the teacher had not been completed, so she hurried to the study to turn on the light. She pulled the switch wire twice, but the light still didn't turn on, then pulled it 5 more times, but it still didn't turn on, because the electricity was cut off. You said, if the electricity comes at night, will the lights in the study be on or not? Why?
傍晚，小兰记起老师布置的作业还没完成，于是急忙跑到书房里打开电灯．她拉了2下开关线，灯还没有亮，接着又拉了5下，还是不亮，因为停了电．你说，如果晚上来了电，书房的灯是亮还是不亮？为什么？
<gadget id="calculator">2 + 5</gadget>
<output>7</output>

<result>7</result>