Unit 4 ,Astronomy: the science of the stars,话题语篇导读,Will the continents join again in the far future? In the beginning，more than 4.6 billion years ago，the world was a ball of burning gas，going round and round through space.At first，hot gases were able to escape into outer space，but as the Earth cooled，they were held by gravity to form the early atmosphere.Clouds began to develop as water vapour collected in the air.And then it began to pour with rain，causing the early oceans to rise up.,It took hundreds of millions of years for the first land masses to appear.About 250 million years ago，long，long after the Earth had formed，all the continents of the time had joined together to form a supercontinent called Pangaea. This supercontinent broke up about 200 million years ago to form two giant continents，Gondwana and Laurasia.Gondwana was made up of what is now Africa，South America，Australia，Antarctica and India.The Indian subcontinent lay off the east coast of Africa，before it broke off and moved north rapidly.,It collided with Asia，creating one of the worlds greatest mountain ranges，which extends for more than 2,400 kilometersthe Himalayas.By now，our world had started to look like something we would recognize.The amazing process of plate tectonics(板块构造)，in which the Earths land masses move slowly across the Earths crust(外壳)，is still continuing. Far in the future，some scientists have predicted that the present continents will join again，to form a new supercontinent. Only time will tell.,Notes 1.Pangaea n.海洋泛大陆；盘古大陆 2.giant adj.巨大的 3.collide vi.碰撞，相撞,Task 判断正(T)误(F) 1.The early oceans appeared because of the rain which developed from hot gases.( ) 2.Pangaea was made up of what is now Africa，South America，Australia，Antarctica and India.( ) 3.Only time will tell whether the present continents will join again.( ),答案,F,T,T,Period One Warming Up，Pre-reading & Reading,课前预习 基础落实,课堂讲义 核心突破,当堂达标 检测巩固,.单词检测 1. n. 天文学 2. n. 系统；体系；制度 3. n. 宗教；宗教信仰 4. n. 学说；理论 5. adj. 猛烈的；激烈的；强暴的 6. n. 大气层；气氛 7. prep. 与不同；不像,答案,词语识记,课前预习 基础落实,astronomy,system,religion,theory,violent,atmosphere,unlike,答案,8. adj. 基本的；基础的 9. adj. 有害的 10. n. 链子；连锁；锁链 11. vi.&vt. 乘；增加 12. vi. 生存；存在 13. adv. 因此；于是 14. n. 迷；难题vt.&vi. (使)迷惑；(使)为难,fundamental,harmful,chain,multiply,exist,thus,puzzle,答案,.短语检测 1.solar 太阳系 2. time 及时；终于 3.all of 各种各样的 4. eggs 下蛋 5.give to 产生；分娩 6. ones turn 轮到某人 7.prevent. 阻止；制止,system,in,sorts,lay,birth,in,from,.阅读课文，匹配各段落大意 Para.1( ) A.The formation(形成) of the earth. Para.2( ) B.The importance of water for life. Para.3( ) C.A widely accepted theory about the formation of the universe. Para.4( ) D.The arrival of humans and their impact on the earth. Para.5( ) E.The development of plants and animals on the earth.,答案,课文预读,C,A,B,E,D,.阅读课文，判断正(T)误(F) 1.It was not until between 4.5 and 3.8 billion years ago that people knew what the earth was to become.( ) 2.Water began to appear on the surface of the earth before gases were produced.( ) 3.The global warming will have a great effect on human beings.( ),答案,T,F,T,答案,.课文阅读理解 1.What began to appear on the earths surface when it cooled down? A.Water. B.Gases. C.Acids. 答案 A,1,2,3,4,5,答案,2.From the last paragraph we can infer that the author is . A.confident B.sad C.concerned,1,2,3,4,C,5,答案,1,2,3,4,3.What does the word “they” in the sentences “It exploded loudly with fire and rock.They were in time to produce carbon dioxide，nitrogen，water vapour and.” refer to? A.Planets. B.Fire and rock. C.Gases. 答案 B,5,答案,4.Which is the right order of the development of life? A.Small clever animalsshellfishdinosaursmammals. B.Shellfishdinosaurssmall clever animalsmammals. C.Shellfishdinosaursmammalssmall clever animals. 答案 C,1,2,3,4,5,答案,5.Why were mammals different from other life forms? A.Because they gave birth to young baby animals and produced milk to feed them. B.Because they produced young generally by laying eggs. C.Because they were able to live on land as well as in the water. 答案 A,1,2,3,4,5,答案,.阅读课文，完成框架图,atoms,dust,globe,carbon,atmosphere,答案,plants,oxygen,land,forests,Human beings,.难句分析 1.What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe. 句式分析：这是一个复合句。what引导 从句，在从句中作 。what引导的名词性从句除了作主语外，还可以作 等。 自主翻译：,主语,宾语,宾语、表语,随后它会变成什么没人能知道，直到4538亿年前，这团尘埃才慢慢地形成一个固体的球状物。,答案,2.The earth became so violent that it was not clear whether the shape would last or not. 句式分析：这是一个复合句。此处为连词so.that.引导的 从句，其中从句中的it为 ，连词whether引导的从句为真正的主语。 自主翻译：,答案,结果状语,形式主语,地球开始变得如此激烈动荡以至于不知道这个固体形状是否会继续存在下去。,答案,3.So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved. 句式分析：这是一个复合句。第一个whether引导 从句；第二个whether引导 从句。 自主翻译：,