Section_ⅠWarming__Up_&_Reading_-_Pre­reading

　　[原文呈现]

　　HOW LIFE BEGAN ON THE EARTH

　　No one knows exactly how the earth began, as it happened so long ago①.However, according to② a widely accepted③ theory④， the universe began with⑤ a "Big Bang⑥" that threw matter in all directions⑦.After that, atoms⑧ began to form and combine to create stars and other bodies.

　　For several billion⑨ years after the "Big Bang"， the earth was still just a cloud of dust⑩.What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe⑪.The earth became so violent⑫ that it was not clear whether the shape would last or not⑬.It exploded loudly with fire and rock.They were in time to⑭ produce carbon dioxide⑮， nitrogen⑯， water vapour⑰ and other gases, which were to make the earth's atmosphere⑱.What is even more important is that as the earth cooled down⑲， water began to appear on its surface.

　　①as it happened so long ago是as引导的原因状语从句。

　　②according to"根据"，后跟名词、代词等，不跟me, us, view, opinion等词。

　　③widely accepted广泛接受的

　　④theory/'θIərI/ n．学说；理论

　　⑤begin with (＝start with) 从......开始，起源于

　　⑥Big Bang宇宙大爆炸；创世大爆炸

　　⑦in all directions (＝in every direction)朝四面八方

　　⑧atom/'ætəm/ n．原子

　　⑨billion/'bIlIən/pron.&n.&adj.〈英〉万亿；〈美〉十亿

　　⑩a cloud of dust一团尘埃

　　a cloud of 一般用来修饰不可数名词。

　　⑪globe/ɡləʊb/ n．球体；地球仪；地球

　　global/'ɡləʊbl/ adj.全球性的；全世界的

⑫violent/'vaIələnt/ adj.猛烈的；激烈的；强暴的