book3unit4radingbook3unit4reading.ppt

Warming up Do you know what it was like before life appeared on earth? medicine biology chemistry Pre-reading 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 million years ago) Which were the first creatures or plants on Earth?... 2. Each religion and culture has its own ideas about how life began on earth. What do you know? In China, we all know that Pangu separates the sky from the earth. 中国神话传说中有盘古开天地的说法。巨人盘古用一把利斧劈开混沌,将天地分开。死后,他的气息化成风和云,声音变成轰轰的雷声,左眼化为太阳,右眼化为月亮,手足与四肢变成大地的四极与五方的名山,血液化成江河,筋脉铺成道路,肌肉形成田地,须发成为星星,牙齿和骨骼化为金属、珍珠、玉石,汗水成为滋润万物生长的甘霖和雨露。 India Brahma is the god first represented in the Hindu Triad. He is the creator of the universe and all living beings are said to have evolved from him. Scanning 1. What was there on the earth before life could begin? Water vapour, carbon dioxide, oxygen, nitrogen and other gases. 2. Why do scientists think there has never been life on the moon? Because there is no water on the moon. 3. Why did animals first appear in the seas? Because water allowed the earth to dissolve harmful gases into the oceans and seas. 4. Why did green plants help life to develop? Because green plants can take carbon dioxide from the atmosphere and fill the air with oxygen. 5. Why were mammals different from other animals? They were different because they produced their young from within their bodies. Reading 1. Read the passage carefully and analyse its structure. Write down the main idea for each paragraph. A widely accepted theory about the formation of the universe The formation of the earth The importance of water for life The development of plants and animals on the earth The arrival of humans and their impact on the earth Reading and answer the following questions. 1. Why was the eart