根据所给的中文提示，写出单词的正确形式，每空限填一词。

Everything in the future will be different from that today. The (空气) will be clean and the weather will be warm all year. There'll be no more light (雨水) and cold (风) in spring, and the sea level will (上升) as well. People won't travel by bus, by car or by bike. It will be (便宜的)to travel (到处)by plane, not only over (陆地), but also into (太空). There will be lots of (机器人) and (机器). They will do all the (繁重的) and difficult jobs. People just need to do some (轻松的)and (简单的) work, and the working (小时)will be (短的), so people will have long holidays.