大气对地面的保温作用主要是由于（　　）

阅读理解

     Hello! My name is John, I have a happy family. There are four people in my family. They're my father, my mother, my baby sister and I. We have a beautiful garden. There are two trees and some flowers in it. There are some apples on the tree. Do you like apples and flowers? Welcome to my home.

第一轮：由全班50位同学匿名投票，每人选2名同学（不弃权，不重复），挑选出票数最高的2位同学．已知5位候选人的得票数如图．

第二轮：根据行规、学规、任课老师打分3个角度综合分析评选，两位同学的情况如下表．

 某“迪厅”主人在地板中安装了一种“神奇”装置，给厅内炫光灯供电．当跳舞的人踩踏地板越厉害时，炫光灯就会亮得越多，也越明亮．该“神奇”装置可能利用的工作原理是（　　）