阅读下面短文，把四个句子填入文中空缺处（1-4），使短文内容完整正确，然后完成第5题。 I think life will be very different in one hundred years' time. Some things will be better and some things will be worse. Firstly, people won't live on the surface of the earth, 1_____ Special machines will provide oxygen and light but the environment won't be the same. Trees and plants won't grow because there won't be any soil. 2_____ Food will mainly be in the form of pills. If the sea isn't too polluted, people will also eat fish. What is more, I think people's everyday life will be different. 3_____ No one will have to do housework either. So, people will have more free time and they will be able to enjoy the things they like -sports, for example. Finally, I believe that everyone will be able to travel to the moon, to other planets and perhaps even to other galaxies for a holiday. In conclusion, 4_____ Whatever happens, though, I'm sure the future will be an interesting place to live in. 5. What is the best title of the passage? [     ] A. Life under the sea B. The future world C. Future life in my mind D. An interesting place to live in