题目

数列{an}中,an＞0,且{anan+1}是公比为q(q＞0)的等比数列,满足anan+1+an+1an+2＞an+2an+3(n∈N*),则公比q的取值范围是(    ) A.0＜q＜                                        B.0＜q＜ C.0＜q＜                                      D.0＜q＜ 答案：解析:∵{anan+1}的公比为q, ∴an+1an+2＝qanan+1,an+2an+3＝q2anan+1. ∵an＞0,∴q＞0且1+q＞q2, 解得0＜q＜. 答案:B通读全文，根据短文理解，选择正确的答案填空。 I had never noticed her. She was not the kind of girl who could draw attention. She was not tall 1 looked ordinary. In class, she liked sitting at the back, reading or writing notes. One day I asked her 2 aloud the text. When I heard her standard （标准） American English, I looked at her with new eyes. And I remembered her name﹣Kelly. Later on, the National College Speech Competition would be held. One student in our school 3 to attend. I thought it over and filled in her name. Kelly practiced 4 for the competition. However, I was a little worried 5 she was always too quiet. Could she really 6 well in the competition?7 the night of the competition, I sat in the front row of the hall very early. I told her to take it easy. Her face turned red and she said nothing. 8 seemed that she was really nervous. I felt upset, but I just patted her on the shoulder and 9 her go to draw lots （抽签）. As a result, she drew No.9 while No.8 was a boy who was very good at giving speeches.Sure enough, No.8 was very 10. The whole audience made a warm applause.While they 11 about his speech with excitement, Kelly appeared on the stage. I with no courage to look at her. It was her 12 time to go up the stage, so I couldn't be angry with her for any small mistakes. But at that moment, I found 13 I was so afraid of her failure（失败）.The strong spotlight and large hall made her so small that nobody seemed to notice she had been on the stage. I felt 14.But the moment that surprised me came. I clearly heard a voice, a very loud voice, "Now, please focus on me."Three times in all, louder and louder.The whole audience fell silent.I could hardly believe that loud voice came from the girl, who was usually soft-voiced and didn't catch attention at all. She gave a perfect speech.I think I will never forget this touching lesson which my student taught me-never underestimate（低估） the power of the 15 people.（1）A.or B.but C.as well D.and （2）A.read B.reading C.to read D.to reading （3）A.allow B.allowed C.was allowed D.allows （4）A.hard B.hardly C.harder D.hardest （5）A.though B.because C.when D.if （6）A.did B.be done C.do D.doing （7）A.In B.At C.By D.on （8）A.That B.This C.It's D.It （9）A.ask B.stop C.want D.let （10）A.success B.successful C.succeed D.successfully （11）A.talked B.would talk C.as well D.were talking （12）A.one B.the one C.first D.the first （13）A.when B.that C.why D.what （14）A.hopeful B.hopeless C.satisfied D.unsatisfied （15）A.silent B.outgoing C.active D.clever