题目

  A native of Florida, U. S. , Hannah Herbst, 17, uses water power to deal with energy poverty. Herbst has risen to fame with the development of BEACON, an ocean energy probe that seeks to offer a stable power source to developing countries by using untapped energy from ocean currents. She told Teen Vogue , I was really involved in theater and athletics and I'm still really into those things. When I was in the seventh grade, I was put into a summer camp. The minute I got there I realized that I was the only girl in the program. I wanted to quit at that moment. But my dad told me, ' Ju07北京理综38  为研究影响家用保温瓶保温效果的因素，某同学在保温瓶中灌入热水，现测量初始水温，经过一段时间后再测量末态水温。改变实验条件，先后共做了6次实验，实验数据记录如下表： 序号 瓶内水量（mL） 初始水温（℃） 时间（h） 末态水温（℃） 1 1000 91 4 78 2 1000 98 8 74 3 1500 91 4 80 4 1500 98 10 75 5 2000 91 4 82 6 2000 98 12 77 下列研究方案中符合控制变量方法的是 A．若研究瓶内水量与保温效果的关系，可用第1、3、5次实验数据 B．若研究瓶内水量与保温效果的关系，可用第2、4、6次实验数据 C．若研究初始水温与保温效果的关系，可用第1、2、3次实验数据 C．若研究保温时间与保温效果的关系，可用第4、5、6次实验数据