阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。

    How cool would it be if people could（travel）in tubes（管道）? They may travel to another city in just（minute）. In the near future, this might not only happen in films,also in real life. The first open air test of the tube train took placeMay 11, 2016. It happened in the Nevada desert, the USA. Elon Musk（have）the idea of developing the tube train. He isfounder（创始人）of the American space company SpaceX. He calls the tube train the Hyperloop. The Hyperloop will be even（fast）than planes. It will go about 1, 200 kilometres per hour. Planes usually（flight）800 to 1,100 kilometres per hour. The company Hyperloop One is still（work）on the tube train. They want people to travel（use）the Hyperloop by 2021.