绿色植物的光合作用需要空气中的（）

已知，直线l经过第二、三、四象限，l的解析式是y=（m﹣2）x+n，则m的取值范围在数轴上表示为（   ）

     A good way to pass an exam is to work hard every day in a year. You may fail in an exam if you are lazy for most of the year and then work hard only a few days before the exam. If you want to be good at English, you have to read stories in English, and to speak English as much as possible. A few days before the exam you should go to bed early. Do not go to bed late at night. Before you start answering in the exam, read carefully over the question papers, and try to understand the meaning of each question. When you have finished your exam, read over your answers. Correct the mistakes and be sure that you don't miss anything out.

2011年，陕西西安被教育部列为“减负”工作改革试点地区．学生的学业负担过重会严重影响学生对待学习的态度．为此我市教育部门对部分学校的八年级学生对待学习的态度进行了一次抽样调查（把学习态度分为三个层级，A级：对学习很感兴趣；B级：对学习较感兴趣；C级：对学习不感兴趣），并将调查结果绘制成图①和图②的统计图（不完整）．请根据图中提供的信息，解答下列问题：

（1）此次抽样调查中，共调查了多少名学生；

（2）将图①补充完整；

（3）求出图②中C级所占的圆心角的度数；

（4）根据抽样调查结果，请你估计我市近80000名八年级学生中大约有多少名学生学习态度达标（达标包括A级和B级）？