We all enjoy the beautiful show of colours as leaves change each autumn. But did you ever wonder how and why this happens?
Leaves are nature’s food factories. Plants take water from the ground through their roots and take carbon dioxide (二氧化碳) from the air. Plants use sunlight to turn water and carbon dioxide into glucose (葡萄糖). Glucose is a kind of sugar, which plants use as food for energy and growing.
The way plants turn water and carbon dioxide into sugar is called photosynthesis that means “ putting together with light”. A chemical called chlorophyll helps photosynthesis. It gives plants their green colour. As summer ends and autumn comes, the days get shorter and shorter, and trees “know” to begin getting ready for winter.
During winter, there is not enough light or water for photosynthesis. Trees rest during this time and live on the food they store during the summer. They begin to shut down their food-making factories.
As the green chlorophyll disappears from the leaves, we begin to see yellow and orange leaves. Small amounts of these colours have been in the leaves all along. We just can’t see them in the summer, because they are covered up by the green chlorophyll.
The bright reds and purples we see in leaves are made mostly in autumn. In some trees, like maples (枫树), glucose is caught in the leaves after photosynthesis stops. Sunlight and the cool nights of autumn turn this glucose into a red colour. The brown colour of trees like oaks (橡树) is made from waste left in the leaves.
It is the mixture of all these things that makes the beautiful colours we enjoy during autumn.
【小题1】The word “chlorophyll” in the third paragraph means _______ in Chinese.

We have always been warned of the dangers of forest fires. They cause _____ 85 _____ to a forest. They kill many plants and animals in an eco-system, which is a group of living things and their environment. But have you ever heard of a forest fire that can be _____86_____  for a forest? People start some of the fires with a special reason to actually do good to the eco-system.

In fact, fires are a natural part of any eco-system. Without fires, the oldest and largest trees would stop sunlight from reaching the forest floor. Fires can _____87_____ some of these old trees. When the trees die, they provide something good for the earth. New trees can grow strong and healthy in their place.

Some trees even need fires to grow. These trees hold their seeds (种子) inside. Heat from a fire allows the coat of the seeds to open up. Then the seeds fall to the ground and have the _____88____ to grow/

Scientist, who know about nature’s needs, start some of these fires, called controlled burns. A fire is started and kept under control. This way, the fire does not spread out of the area or _____89_____ a after forest fires, they can go hungry _____90_____ their food has been damaged in the fire. Small, controlled fires mean than animals will not have to move far to find food. After some time, small plants begin to grow. Animals return soon after the plants return. This _____91_____  makes an eco-system.

So the next time you hear about a forest fire, think about the good as well as the bad. It may take a new eco-system a while to return, but it will likely come back stronger and healthier than ever.

1.A) illness     B) difficulty      C) damage       D) flood

2. A) helpful    B) powerful      C) harmful       D) awful

3. A) take the place of    B)  get ready for     C)  be bad for      D) get rid of

4.A) time       B) water       C) chance       D) skill

5.A) discover    B) cover       C) but          D) waste

6. A) because    B) although      C) but         D) so

7.A) almost     B) again        C) never      D) even

This is a story from a meeting held by some people and two things in nature. We call it the Four-Sided Talk. Let’s “listen to” everyone carefully and find out what they think.

People: We have lived on the earth since ancient times. The earth is our home. Now we regret what we have done to our home!

1.What’s the United Nations’ decision in the Four-Sided Talk?

A. Set an Earth Day.????????????? ??????????

B. Find out what is making the pollution.

C. Hold an international meeting.??????

D. Protect and love the earth.

2.What doesn't the old tree tell us?

A. He’s afraid to be cut down some day.

B. The trees have the longest lives in the world.

C. Over-cutting teaches people a lesson.

D. People are destroying the natural environment.

3.What will people do according to the passage?

① Over-use the resources.? ② Beautify the earth.

③ Start a global group.??? ④ Protect the earth.

A. ①④????????? B. ②③??????? C. ①③????????????? ?? ???? D. ②④

Life is like the four seasons. Now I am very old, but when I was young, it was the spring of my life. I was born, I played a lot, and then I started school. I learned many new things. Like a flower, I grew bigger every day. There were happy days and sorrowful days: some days the sun shone, and some days it didn’t.
In my twenties, I had a good job. I was strong and happy. Then I married (结婚) and had a child. In those days, I didn’t have much time to think. Every day I was busy and worked very hard. And so, I started to get some white hairs. The summer of my life passed quickly.
Then the days got shorter. Leaves fell from the trees. My child was a university student, and then an engineer. My home was much quieter. I started walking more slowly. One day I stopped working. I had more time. I understood this was my autumn, a beautiful time when the trees change color and give us nice fruits.
But the days kept getting shorter and colder. Winter has come. I am older and weaker. I know I do not have many days left, but I will enjoy them to the end.
【小题1】The writer started walking more slowly in the          of his life.

完形填空
阅读下列短文，从文后各题所给的四个选项中选出一个最佳答案。
Do you know why different animals or pests(害虫) have their special colors? Colors in them seem to be mainly used to ___1___ themselves.
Some birds like eating locusts(蝗虫), but birds cannot ___2___catch them. Why? It is because locusts change their__3___ with the change of the colors of crops. When crops are green, locusts look ___4___. But as the harvest time comes, locusts change into the same brown color __5___ crops have. Some other pests whose colors are ___6__ plants are easily found and eaten by ___7___. So they have to hide themselves for lives and appear only __8____.
If you ___9___ animals’ life, you’ll find the main use of colors is to protect __10___. Bears, lions and other animals ___11___ quietly through forests. They cannot be easily seen by hunters ___12___ their colors are much like the trees.
Colors are useful not only on the land, but also in the __13___. A kind of fish can __14____ a kind of black liquid(液体) when they face danger. The liquid spreads over quickly, so they cannot be found by their enemies and can quickly swim away. That is ___15____ they can live safely though they are not strong at all. So colors are really useful to animals.