Astronomy: Unit 4 the science of the stars Xingning No.1 Middle School: He Zhixin

Game 1: What is the word ? e r t a h earth

Word 1: a m m ml mammal a

Word 2: t m yse system s

Word 3: i s x t e exist

Game 2: Repeat the words harmful surface depend What are the words?

Group 1: mammal development solar system

Group 2: method reptile violent Big Bang

Group 3: planet amphibian explode atmosphere global

1. Many scientists believe that the universe began with a huge explosion called the Big Bang. When did it happen? A. about 1.5 billion years ago B. about 15 billion years ago C. about 4 billion years ago Have a quiz

2. Each religion or culture has its own ideas about the beginning of the universe.Can you give one or two examples? In Chinese legend, it says ____________ created the world. He seperates the sky from the earth and his whole _____ turns into all kinds of things in the universe. Pangu （盘古） body

2. Each religion or culture has its own ideas about the beginning of the universe.Can you give one or two examples? the God Adam and Eve In Bible,the world and the whole universe was created by __________, who created the first man and the first woman called ________________.

3. When did the earth come into being? A. about 10 billion years ago B. about 20 billion years ago C. about 4.5 billion years ago 4. When did life begin on the earth? A.about 1 billion years ago B. about 2 billion years ago C. about 3 billion years ago Have a quiz

ON THE EARTH How LIFE BEGAN ?

Go! Time is up! scanning

Go! Time is up! Comprehening Ex.1

Paragraph 1 1)What is the main idea of Para.1? 2) Why was water important on the earth? Questions

A cloud of dust After the “Big Bang”, the earth was just a cloud of energetic dust.

A solid ball What it was to become was a mystery until the dust began to slowly combine into a ball moving around the sun.

Violent earth The problem was that the earth became violent because it was not clear whether the solid shape was to last or not. It exploded loudly with fire and rock,

Atmosphere Which were in time to produce the water vapour, carbon dioxide, oxygen, nitrogen and other gases, which were to make the earth’s atmosphere.

Presence of water As the earth cooled down, water began to appear on its surface. Nobody knew that it was going to be different from other planets going round the sun.

Water stayed Water had already disappeared from planets like Mars or satellites like the moon,but it stayed on the earth. MoonMars

special This is how the earth began to show its special qualities. Many people think that this was important for the beginning of life.

Harmful gases It allowed the earth to dissolve harmful gases, which had become part of the earth’s atmosphere, into the oceans and seas.

Possible life That made it possible for life to begin to develop.

Paragraph 1 1)What is the main idea of Para.1? 2) Why is water important on the earth? Questions It talks about how water came into being on the earth and its importance to the development of life. Because water allowed the earth to dissolve harmful gases into the oceans and seas.

Small plants grow on the water What scientists think is that the earth was different because of the arrival of small plants growing in the water on its surface.

Oxygen Nobody understood that these plants were the start of many changes.They multiplied and filled first oceans and seas with oxygen.

Shellfish and other fish appear This encouraged the development of early shellfish and all sorts of fish.

Plants began to grow on dry land Many millions of years later the first green plants began to appear on land.

Carbon dioxide Scientists believe that taking carbon dioxide from the atmosphere and filling the air with oxygen helped life to develop.

Insects appear Later land animals appeared. Some were insects.

Amphibians appear Others, called amphibians, were able to live on land as well as in the sea.

Reptiles appear When the plants grew into forests, reptiles appeared for the first time. They produced young generally by laying eggs.

Dinosaurs appear Later, some huge animals, called dinosaurs, developed. They laid eggs too.They became the most important animals on the earth for millions of years.

Mammals appear But when they disappeared, mammals became more important. They were the last group of animals

Produce young and they were different because they produced their young from within their bodies.

1)Why is it wrong in films and stories to show dinosaurs and people together? Bacause dinosaurs died out long before human beings developed on the earth. Questions

2)What is the main idea of Para.2-3? Questions It tells us something about the evolution （进化） process （过程） of plants and animals.

Fill in the blanks __________ 6 _______ small plants in _____ _______ and all sorts of fish green plants on _____ insects _________ ______ dinosaurs water shellfish land amphibians forests reptiles ______mammals

1 a cloud of dust The time line of the development of life on the earth 2 a solid ball 3 presence of water 4 small plants grow on the water 5 shellfish and other fish appear 6 plants begin to grow on dry land 7 insects and amphibians appear 8 reptiles appear 9 dinosaurs appear 10 mammals ( including humans ) appear

Animals with four legs and feet Small clever animals, now with hands and feet, appeared and spread all over the earth.

Humans appear They developed new methods of growing food, hunting and moving around.As time went by they covered the earth and have become the most important animals on the planet.

Greenhouse effect But they are not taking care of the earth very well. They are putting too much carbon dioxide into the atmosphere, which prevents heat from escaping from the earth into space.

Too hot The earth may become too hot for the lives on it.

future Whether life will continue on the earth for million years to come will depend on whether this problem can be solved.

Discussion What will our future be if the earth may become too hot for lives on it? How to solve （解决） the problem of global warming?

Summary After the “Big Bang”, the earth was just a cloud of ________ dust. It ________ loudly with fire and rock, which were in time to produce the water _______, carbon dioxide and other gases. Then small plants grew. They multiplied and _____ the oceans and seas with oxygen. Many millions of years later the first green plants began to ______ on land. When the plants grew into forests, ________ appeared for the first time. They produced young generally by _____ eggs. energiticexploded vapour filled laying reptiles appear

Summary when dinosaurs disappeared, ________ became more important. Now small clever animals with ____________ appeared and ______ all over the world. As time went by they covered the earth and they are putting too much carbon dioxide into the __________, which ______ heat ______ the earth into space. Whether life will continue on earth for millions of years to come will ____________ whether this problem can be solved. hands and feet depend on frompreventatmosphere spread mammals

Homework 1.Continue the discussion “ How to solve the problem of global warming. ” with your classmates. 2. Retell the passage using about 100 words.