近年来，自由职业者在网络平台上出租私家车、出售自家厨房制作的菜肴等“零工经济”现象日益兴盛。据研究推算，类似经济模式未来10年在全球范围内将创造7200万就业岗位。这种经济模式带来的积极影响有（  ）

①避免情绪化消费，促进消费结构的调整

②转变企业用工方式，降低企业用工成本

③缩小劳动者的收入差距，促进社会公平

④助力我国大众创业、万众创新政策落实

如图是6月22日五个不同地点的昼夜长短示意图（阴影部分表示黑夜，空白部分表示白昼），据图判断下题．

Do you know the game "Rock, paper or scissors"? Maybe you think it's just a simple game for children. But in fact, some adults use it to make decisions and solve their problems. It is also popular in many countries.
There are different stories about the history of the game. But many people believe the game  came from Japan, and Japanese have played it for a long time. Later it came to Europe in the middle of the 18th century. In 1842, England founded the Paper Scissors Stone Club and from then on people could get together to play the game for honor (荣誉).
There is even an international club named the World Rock Paper Scissors Club in Toronto. The club makes "Rock, paper or scissors" more and more popular. It holds the world championship (锦标赛) every year. Top players from around the world take part in it and the champion (冠军) can get a lot of money and the honor of all the fans of "Rock, paper or scissors".

如图所示，某一导体的形状为长方体，其长、宽、高之比为a∶b∶   c=5∶3∶2，在此长方体的上下、左右四个面上分别通过导线引出四个接线柱1、2、3、4，在1、2两端加上恒定的电压U，通过导体的电流为I₁；在3、4两端加上恒定的电压U，通过导体的电流为I₂，则I₁∶I₂为(　 　)