题干

当今社会手机越来越普及,有很多人开始过份依赖手机,一天中使用手机时间过长而形成了“手机瘾”.为了解我校初三年级学生的手机使用情况,学生会随机调查了部分学生的手机使用时间,将调查结果分成五类:A、基本不用;B、平均一天使用1~2小时;C、平均一天使用2~4小时;D、平均一天使用4~6小时;E、平均一天使用超过6小时.并用得到的数据绘制成了如下两幅不完整的统计图(图1、2),请根据相关信息,解答下列问题:

上一题 下一题 0.0难度 选择题 更新时间:2019-03-03 02:43:43

答案(点此获取答案解析)

同类题5

阅读理解
    When I was in middle school, a poisonous spider bit my right hand. I ran to my mom for help —but instead of taking me to a doctor, my mom set my hand on fire. After wrapping my hand with several layers of cotton, then soaking it in wine, she put a chopstick into my mouth, and ignited the cotton. Heat quickly penetrated the cotton and began to roast my hand. The pain made me want to scream, but the chopstick prevented it. All I could do was watch my hand burn —one minute, then two minutes— until mom put out the fire.
    You see, the part of China I grew up in was a rural village, and at that time preindustrial. When I was born, my village had no cars, no telephones, no electricity, and even no running water. And we certainly didn't have access to modern medical resources. There was no doctor my mother could bring me to see about my spider bite.
    For those who study biology, you may have grasped the science behind my mom's cure: heat deactivates(使失去活性) proteins, and a spider's venom (毒液) is simply a form of protein. It's cool how that folk remedy actually incorporates basic biochemistry, isn't it? But I am a PhD student in biochemistry at Harvard, I now know that better, less painful and less risky treatments existed. So I can't help but ask myself why I didn't receive one at the time.
    Fifteen years have passed since that incident I am happy to report that my hand is fine. But this question lingers, and I continue to be troubled by it. We have learned to edit the human genome(基因组) and unlock many secrets of how cancer progresses. We can control neuronal activity literally with the switch of a light. Each year brings more advances in biomedical research—exciting, transformative accomplishments. Yet, despite the knowledge we have accumulated, we haven't been so successful in distributing it to where it's needed most. According to the World Bank, twelve percent of the world's population lives on less than $ 2 a day. Malnutrition kills more than 3 million children annually. Three hundred million people are suffering malaria globally. All over the world, we constantly see these problems of poverty, illness, and lack of resources preventing the flow of scientific information. Life-saving knowledge we take for granted in the modern world is often unavailable in these underdeveloped regions. And in far too many places, people are still essentially trying to cure a spider bite with fire.