生物群落是一个不断发展变化的动态系统。下列有关群落演替的叙述错误的是（   ）

如果一个数的相反数是负数，那么这个数一定是(    ).

不管是巴黎街头“请勿喧哗”的中文标语，还是纽约地铁站内“请勿插队”的中文劝导牌，仍然都在警示我们：必须进一步提高国民的文明素质。这是因为（      ）

任务型阅读。（5分）
Charles，Isabel，Alex，Tara和Toby五个人都爱好体育。现在他们正打算从事各自喜欢的项目。请仔细阅读第76--80题中的个人情况说明，然后选出符合各人要求的最佳选项。
【小题1】Charles works in the city center and wants to take up a sport that he can often do during his lunch break. He enjoys a game in which he can play with his workmate on the desk to relax.
【小题2】 Isabel, aged 17, is a Chinese girl who studies in the US now.  She never misses any matches played by Houston Rockets.  She hopes to follow in Yao Ming’s steps.
【小题3】Alex likes water sports very much.  He is good at showing different styles, such as butterflies, frogs and so on. Believe it or not, he can dive under water for 2. 5 minutes.
【小题4】Tara comes from America. Now she teaches English in a middle school in Beijing.  In her free time, she would like to go in for a traditional sport so that she can learn more about China.
【小题5】 Toby is a student in charge of PE lesson in Riverside Middle School. These days he is training hard for the coming sport meet. He wants very much to break the school record of 175cm.
    
A                B               C               D             E

处于青春期的我们，经常会因与父母的意见相左而倍感烦恼。对此，解决问题的最好办法是(       )