十七岁的刘某是某重点中学的在校学生，犯罪前，成绩始终居全班前五名。后来，他在外结识了一帮朋友，经常去吃喝玩乐。渐渐的刘某觉得在学校上晚自习不自由，于是由内宿转外宿，由于朋友们经常相互请客，他们个个被钱所困。当这帮朋友提出通过偷车解决经费时，刘某没有觉得这种行为是违法的，反而认为朋友提出的就不能反对，就应该执行。就这样，刘某把法律和道德抛在脑后，跟他们一起盗窃自行车。一宗又一宗的盗窃案最终使刘某被判有期徒刑四年，此时刘某才噩梦初醒。

结合上述材料，回答下列问题

2016的相反数是（　　）

密西西比河水流平稳，利于航行，主要原因是（   ）

【实验器材】额定电压为2.5V的小灯泡（正常发光时电阻约为6Ω）、滑动变阻器（“10Ω  2A”）、新干电池两节、开关、导线若干等．

【实验步骤】

根据短文后所给的任务，完成1-5小题

        What will our world be like in 2020? Maybe no one knows. Because we never know what will happen in the future. But it's very interesting to make some predictions. Here are some exciting predictions.
Languages
        English should still be the most popular language, but Chinese should be the second. Now, many foreign people are studying Chinese    A   their second language.
Water
        ①Water will become as expensive as oil because many rivers will disappear. We will haveto save water and pay more for clean water.
Education and Science
        Students won't go to school. They will stay at home and study online. Students from all over the world may study together    B   the Internet. We may eat more genetically (转基因) modified food. And more robots will be around us. ②Lots of danger housework will be done by them.
Living
        People will live and work under the sea. Perhaps there will be big towns, factories and farms under the sea, too. Everyone will carry a pocket computer. ③computer, the, answers, will, all, the, to, their, people, problems, give. Everyone will have telephones in the pockets, too, and they will be able to talk to their friends all over the world.