题目

现有CH4和C2H6（乙烷）组成的可燃性混合气体，该混合气体中氢元素的质量分数可能是（相对原子质量：C—12，H—1）（     ） A．18%             B．20%            C．25%            D．22% 答案：D从方框里选择合适的句子填空完成对话。（有两项多余）A: Daddy, how far are we from the theater?B: Let me see. 1..A: It will kill me, daddy.B: No, it won’t. It’s a challenge (挑战). 2..A: But daddy, I am tired. Is there a bus here?B: 3.. But it will take more time.A: Oh, my God. 4..B: Do you want to? A taxi will certainly take us there quickly. But walking isn’t bad. It is a good chance to challenge yourself. A: 5.. Will we be late for it? B: Don’t worry about being late. We have plenty of time. Let’s go!A. Do you know when the play starts? B. I wonder why we don’t take a taxi.C. Of course, there is one.D. We have to walk twenty more minutes.E. And I am sure you can prove yourself a real young man.F. Do we really have to run?G. No, there isn’t. 1.D 2.E 3.C 4.B 5.A 【解析】试题分析：在对话中，B问离剧院还有多远，他老是寻找理由不愿意步行，爸爸对他进行了教育。 1.根据A的问话how far are we from the theater?，是问离剧院的距离。备选句子中，We have to walk twenty more minutes.说的是距离，故选D。 2.根据B的话I...