Unit 20　New Frontiers
单词注释
难句剖析
导读诱思
在未来,人们生活将会变得愈加方便,愈加丰富多彩。Nowadays we humans have stepped into the 21st century.With the rapid development of technology,great changes will take place with certainty1 in the future,which may be a bit enjoyable and surprising.As you can imagine,you can travel to any place by spaceship in your spare time,even a vacation on the moon.If you want to explore the ocean,you can go to the bottom of it where there are a number of cities and many people live there.What’s  ...