Scientists say life will be very different in 2050.

    First，there will be no TV channels（频道）in 2050.People will choose a program from a computer and watch it on TV.In 2050，we will get information from the computers only.

    Second，water will be a big problem in 2050.In many places，people won't have water to drink.

    Third，cars will use new and clean fuels and they will go very fast.There will be a computer in every car.And the computers will control the cars and there won't be any accidents（事故）.

全民参保登记计划确定的目标是，基本养老保险每年新增参保2000万人，到2017年底超过9亿人；基本医疗保险重点解决重复参保和漏保并存的矛盾，使人人享有基本医疗保障；失业保险、工伤保险、生育保险参保人数，到2017年年底分别达到1.8亿人、2.3亿人和2亿人。这样做（   ）

①有利于落实以人为本的科学发展观  

②是维护社会公平、促进社会和谐的表现

③有利于促进全体人民共享改革发展成果 

④能彻底解决社会主义初级阶段的主要矛盾