2016-2017学年 人教版 必修三 Unit 4 Astronomy :the science of the stars Reading 课件 (9)
2016-2017学年 人教版 必修三  Unit 4 Astronomy :the science of the stars  Reading 课件 (9)第5页

1. The origin of life on earth is a question that interests astronomers. What do you know about it? ● How old is the universe? (several billion years ago) ● How old is the Earth? (between 4.5 and 3.8 billion years ago) ● Which were the first creatures or plants on Earth? (extremely small plants)…

Pre-reading