我来到了40世纪,这时的地球已经发生了翻天覆地的变化。人类为了保护地球便把火星建成了第2个家,从地球到火星,只需要几分钟的时间。在这个地方,已经没有了自行车、电动车、摩托车、私家车、出租车,在马路上除了公交车之外,就只有行人。其实秘密就在人们脚下所穿的鞋子上。这鞋子的表面是用纳米结构制成的,具有抗菌、保 I came to the 40th century, when the earth has undergone tremendous changes. In order to protect the Earth, mankind built Mars into its second home, from Earth to Mars, in just a few minutes. There are no bicycles, electric cars, motorcycles, private cars and taxis in this place. There are only pedestrians on the road besides buses. In fact, the secret is on the shoes worn by people. The surface of the shoes is made of nano-structure, with antibacterial, Paul