Level3 Unit3 Part1 Listening - Life & Conditions 1
There are many forms of life on Earth, including human beings.
Life exists in a variety of conditions.
Some forms of life live in a watery environment, like the oceans.
Other forms of life can be found in very dry areas like derts.
However, for any form of life to exist, conditions must be right.
When conditions are not right, that form of life will become extinct.
To become extinct means to die out completely.
Conditions must be right for life to exist.
Millions of years ago there were forms of life that no longer exist. 恐龙绘本
When conditions changed, the forms of life died out.
One extinction event happened about 250 million years ago.
This was the largest extinction event of all time.
Many forms of life became extinct.
96% of all life in the oceans died out.
Most incts also became extinct.
This event happened over a period of veral million years.
The caus of this extinction event are still unknown.
Possible caus include large volcanic eruptions and global warming.
Some scientists believe that there were veral caus.
They believe that a ries of events caud the extinctions.
Scientists are working to better understand what really happened.
Level3 Unit3 Part1 Listening - Life & Conditions 2
In modern times we humans face changing conditions.
For humans to live, we need clean air and clean water.
Pollution is now a growing problem around the world.
Pollution poisons the air and water that we depend on.
Polluted air makes people sick and afraid to go outside.
Polluted water poisons our food supply.
As a result, we never know which foods are safe to eat.
Human beings cannot live in a poisoned environment.
Therefore, pollution is a major threat to our existence.
Humans need temperatures to be in a comfortable range.
To be in a comfortable range means to be neither too hot nor too cold.
With global warming, global temperatures are rising.世界上最冷的冷笑话
As temperatures ri, the polar icecaps will melt.
As the polar icecaps melt, ocean levels will ri.
Areas of some countries will soon be under water.
People will be forced to relocate from flooded areas.
汽车买卖合同范本
In nature, even small changes can sometimes have large effects.带春字的诗句
It’s difficult to predict what’s going to happen.
The entire ecosystem that we depend on is changing.
红梅花Some of the changes are irreversible.
Irreversible changes cannot be undone.
Let’s hope that humans are smart enough to understand how the world is changing.
With more understanding, we can make better choices about what to do.
We can face the challenges of pollution and global warming.
We need to do this before it’s too late.
This planet Earth is our only home and we need to protect it.
Level3 Unit3 Part1 Vocabulary - Forms of Life
Mammals are covered by hair or fur, have a backbone and are warm-blooded.
All female mammals produce milk for their young.
Reptiles are covered by scales and include snakes, lizards and turtles.
Reptiles have a backbone and are cold-blooded, which means they often rely on external sources of heat.
Birds are covered by feathers and are warm-blooded.
Most birds can fly and many types of birds migrate great distances.
Most incts such as ants and bees have a small, 3-part body with 3-pairs of legs.
Some incts, like mosquitoes, spread dias that cau the deaths of many humans.
Unlike animals, plants get the energy that they need from the sun.
Plants convert light energy, along with carbon-dioxide and water, into chemical energy.
Level3 Unit3 Part1 Vocabulary – Instruments
Scales and rulers are ud to measure weight and length.
Units of weight include kilograms and pounds, and units of length include centimeters and inches.
The instruments are ud to obrve very large and very small objects.
Telescopes are ud by astronomers, and microscopes are ud by biologists and doctors.
The appliances are ud in the kitchens of almost every home.
Stoves are ud to heat food and refrigerators are ud to keep foods cool or cold.
广西民族师范Houhold tools like the are ud to build and repair things.
悬疑推理电影
再别康桥原文朗诵Hammers are ud to pound in nails and screwdrivers are ud to turn a screw.
Level3 Unit3 Part1 Dialogue - Dating Anniversary
