题目

已知关于x的分式方程+=1的解是非负数，则m的取值范围是（ ） A．  m＞2          B．m≥2          C．m≥2且m≠3    D． m＞2且m≠3 答案：C解：分式方程去分母得：m﹣3=x﹣1， 解得：x=m﹣2， 由方程的解为非负数，得到m﹣2≥0，且m﹣2≠1， 解得：m＞2且m≠3．根据对话内容，从方框中选择恰当的选项补全对话，其中有两项多余A: Linda, are you free this evening?B: Not really! Why?A: Some of our classmates are coming to my home for dinner. B: I' m afraid not. A: At about eight o' clock.B: A: What about half past six?B: Oh, I promised my brother I would help him with math at that time.A: B: But I will come over to your house next time.A: You're welcome.A. Sure, I'd love to.B. Can you come, too?C. OK, you are really busy.D. But when will the dinner start?E. I' m going to your house by bike.F. Thank you very much for asking me.G. Oh, sorry, I have a violin lesson at that time.