题目

阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。Lockers(储物柜)have been the symbol of American high school for decades. But walk down any hallway of the new Germantown High School in Madison County, Mississippi, and you won’t spot a single locker. New technology such as e-books, interactive(互动的)assignments and Web-based learning is making lockers in American high school a thing of the past. Officials from schools that have gone lockerless listed several benefits: less noise, less delay and an increased sense of safety. “It's all to2、已知a是有理数，下列各式总正确的是（　　）A、a2＞0B、a-1＞1C、|a-1|≥0D、a+1＞-a-1