Unit4 reading

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 within their bodies.
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.
water 1 small plants in _____ green plants 3 land on _____
6 forests _______
______ 7 reptiles 8 dinosaurs mammals 9 ______
Animals with four legs and feet
mountains; blood became rivers and tendon (筋
脉) became roads; muscles became fields and
hair stars; teeth and bones became metals, pearls
and jade; sweat became rain.
Unit 4
Astronomy: the science of the stars
The Solar system
• eight planets
火星 金星 Mars Venus 水星 Mercury 地球 Earth
木星 Jupiter 土星 海王星 Saturn Neptune
How Life Began on the Earth？？？
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
Questions
6. What was important to the development of fish? oxygen. 7. What made possible the rise of mammals on the earth? The disappearance of dinosaurs made the possible the rise of mammals on the earth.
Bacause dinosaurs died out long before human beings developed on the earth.
Fill in the blanks
_______ and all shellfish 2 sorts of fish
4amphibians 5__________ insects _________
Pangu separated the earth and sky with an ax.
After he died, his breath became wind and cloud;
his voice became thunder and his left eye sun and
right one moon; arms and legs became edges and
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,
4. How did water come into being
on the earth?
As the earth cooled down after
it exploded, water came into being.
5. Why is water important on the earth? It allowed the earth to dissolve harmful gases and acids into the oceans and seas.
It began with a “Big Bang”
2. What form was the earth after the “Big Bang”? The earth was still just a cloud of dust. 3. What made up the earth’s atmosphere after the earth exploded? Carbon, nitrogen, water vapour and other gases.
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.
That made it possible for life to begin to develop.
Scanning
Read the first three paragraphs carefully and answer the questions.
1. What did the universe begin with according to a widely accepted theory?
Pre-reading
How did the universe begin?
Each religion or culture has its own ideas about the beginning of the universe.
Pangu separates the sky from the earth.
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
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.
Water stayed
Moon
Mars
Water had already disappeared from planets like Mars or satellites like the moon ,but it stayed on the earth.
special
This is how the earth began to show its special qualities. Many people think that this was important for the beginning of life.
Small clever animals, now with hands and feet, appeared and spread all over the earth.
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 ofe 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.
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
8. Why are mammals different from all life forms in the past? They gave birth to young baby animals and produced milk to feed them.