阅读下列短文，从下面每小题的A.B.C .D四个选项中选出最佳选项。C It is easier to float in the ocean than in a swimming ...

题型：阅读选择题类：常考题难易度：普通

牛津深圳版九年级上册Module2 Ideas and viewpoints Unit 4 Problems and advice 同步练习

阅读下列短文，从下面每小题的A.B.C .D四个选项中选出最佳选项。

It is easier to float in the ocean than in a swimming pool. Do you know why?

Ocean water is full of salt - and salt water can hold up more weight than fresh water. See for yourself! (Ask an adult to help you.) You will need: 3 cups warm water; A wide-mouth jar（罐）; Salt; A spoon; A potato. You will do: 1. Pour 1.5 cups of warm water into the jar. 2. Add 1/3 cup of salt. 3. Stir(搅拌) until the salt is completely dissolved(完全溶解) 4. Add another l.5 cups of water. Pour it slowly over the back of the spoon into the jar so that the two kinds of water will not mix together. 5. Softly place the potato into the jar. Don't drop it. What will happen: The potato will sink - but only halfway! Why: Salt water is heavier than fresh water, so it will stay on the bottom. The fresh water will remain on the top. The potato is heavier than the fresh water, but it is lighter than the salt water. That is why the potato will sink only halfway down.

（1）、What don't we need for the experiment?

A、Some water. B、Some juice. C、Some salt. D、A potato.

（2）、In the experiment, what should we do right after we first pour l.5 cups of warm water into the jar?

A、Add the salt to the water. B、Stir the water quickly. C、Put the potato into the jar. D、Add some more warm water into the jar.

（3）、Why do we pour the water over the back of the spoon slowly?

A、It is easier to see what you are doing. B、It keeps the water from running out. C、It pushes the fresh water to the bottom. D、It will keep the two kinds of water from mixing together.

（4）、Which of the following is TRUE according to the passage?

A、Salt water can't hold up more weight than fresh water. B、The potato is heavier than the salt water. C、The potato will directly sink in the fresh water. D、The potato directly sinks in the experiment.

（5）、What can we learn from the experiment?

A、Ocean water is full of salt. B、The fresh water and the salt water can't mix together. C、Drinking salt water sometimes is good. D、Salt water can hold up more weight than fresh water.

举一反三

   More than 50,000,000 people live in the rainforests of the world and most of them do not hurt the forest they live in. They eat the fruits that grow on the forest trees, but they do not cut them down. They kill some animals to eat, but they do not destroy them.
When we cut down the rainforests, we destroy these forest people, too. In 1900, there were 1,000,000 forest people in the Amazon forest. In 1980, there were only 200,000.
   The Yanomami live along the rivers of the rainforest in the north of Brazil. They have lived in the rainforest for about 10,000 years and they use more than 2,000 different plants for food and for medicine. But in 1988, someone found gold in their forest, and suddenly 45,000 people came to the forest and began looking for gold. They cut down the forest to make roads. They made more than a hundred airports. The Yanomami people lost land and food. Many died because new diseases came to the forest with the strangers.
   The Yanomami people tried to save their forest, because it was their home. But the people who wanted gold were stronger.
Many forest people try to save their forests. Chico Mendes was famous in Brazil because he wanted to keep the forest for his people. “I want the Amazon forest to help all of us-forest people Brazil, and all the Earth,” he said. A few months later, in December 1988, people who wanted to cut down the forest killed Chico Mendes.
   In Borneo, people were cutting down the forest of the Penan people to sell the wood. The Penan people tried to save their rainforest. They made blockades across the roads into the forest. In 1987, they closed fifteen roads for eight months. No one cut down any trees during that time.
   In Panama, the Kuna people saved their forest. They made a forest park which tourists pay to visit.
The Gavioes people of Brazil use the forest, but they protect it as well. They find and sell the Brazil nuts(坚果) which grow on the forest trees.

In most parts of the world, many students help their schools make less pollution. They join "environment clubs". In an environment club, people work together to make our environment clear.
Here are some things students often do.
No-garbage lunches. How much do you throw away after lunch? Environment clubs ask students to bring their lunches in bags that can be used again. Every week they will choose the classes that make the least garbage and report them to the whole school!
No-car day. On a no-car day, nobody comes to school in a car— not the students and not the teachers! Cars give pollution to our air, so remember: Walk, jog, bike or run. Use your legs! It's lots of fun!
Turn off the water! Do you know that some toilets can waste twenty to forty m³ of water an hour! In a year, that would fill a small river! In environment clubs, students mend those broken toilets. We love our environment. Let's work together to make it clean.

请认真阅读下列短文，从短文后各题所给的A、B、C、D四个选项中，选出最佳选项。
A
  If you travel by air across the center of Africa or South America, you fly over forests for thousands of kilometers. These great forests are the oceans of trees. There are full of thousands and thousands of different kinds of plants and animals.
  However, the world's forests are getting smaller all the time. We are cutting down the trees because we need wood, and we need more farm land. Some people say that there will not be any forests like these in 20 or 30 years. what will happen if they disappear?
    If we cut down our forests, a lot of plants and animals will disappear from the world. In a lot of places the new farm land will soon look like the old deserts. Crops will not grow there. It will not rain very often, and the weather will get very hot. Perhaps the climate of the world will change. This will be dangerous for everyone in the world. That is why we must take care of our forests.

请认真阅读下面短文，从短文后各题所给的A、B、C、D四个选项中，选出最佳选项。

Do you have brown hair? Are you taller than other kids your age? These characteristics were decided before you were born. You got your traits from your parents. They passed their traits on to you through genes (基因).

Genes carry codes (代码) for blue eyes or brown eyes. Genes say how tall you will get and what color hair you will have. You got half of your genes from your mother. You got half of your genes from your father. So you have your own set of genes. Each person gets different genes for each body part. That is why you look like but not exactly like your brother or sister.

A dominant (显性的) gene shows up most of the time. Brown eyes are dominant over bluc eyes. A recessive (降性的) gene shows up less often. Light hair comes from a recessive gene. Dark hair is more common. Look at the eye color and hair color of the people around you. You will see that this is true.

Genes help to make you who you are. But they don't tell the whole story. Your genes may help you to be fast and strong. But you still need to learn how to run or swim or skate well.

阅读理解

Zhalong is a nature reserve in Heilongjiang in northeast China. It is one of the world's most important wetlands*. The reserve offers food and places to live in for wildlife. It is an ideal home for different kinds of plants, fish and birds.

Many birds live comfortably in Zhalong Nature Reserve all year round, but some only stay there for a short time. There are many fish in the wetlands, and the birds can easily catch them for food. Zhalong Nature Reserve is an important living area for red—crowned cranes*. There are not many red—crowned cranes in the world. Some of them live in Zhalong.

Some people want to change the wetlands to make more space for farms and buildings. This means there will be less and less space for wildlife.

More and more birds are in danger because they do not have enough living space. Many of them died. The Chinese government wants to protect these endangered* birds, and they can be safe in Zhalong.

Every year, a lot of visitors go to Zhalong to watch birds. This year, members of our Birdwatching Club are going to study the different kinds of birds in Zhalong and the changes in their numbers.

We do a bird count* once a year. We are now inviting middle school students to help. We need more people to help us count and do something to help the birds. Many people do not understand the importance* of the wetlands. We hope this information will help them understand and make them do something to protect wildlife.

阅读下列短文，根据短文内容，从短文后各题所给的A、B、C、D四个选项中，选择最佳选项。

A black hole is a place in outer space with very strong gravity. Gravity is a great force(力量) that shapes the universe. On Earth, gravity makes apples fall from trees. It keeps your feet planted on the ground. The gravity in a black hole is much stronger. It is so strong that nothing around it can get away from it, not even light.

Black holes are invisible. We can't actually see them because they don't throw back light. But scientists can find them with space telescopes(望远镜)and special tools. The strong gravity makes nearby stars move in a certain way. By studying how the stars move, scientists can find out if they are flying around a black hole. Strange things happen around black holes. This makes black holes a popular subject of science fiction(科幻)stories, although they are very real.

A black hole forms when a star dies. The star falls in on itself and turns into a very small point. Because of its small size and huge mass(质量), the gravity will be so strong that it will pull light in and become a black hole. Black holes can grow huge as they continue to pull other things in and "eat" them. Many scientists believe that there are super-massive black holes at the center of galaxies, including the Milky Way.

The idea of the black hole was first suggested by two different scientists in the 18th century: John Michelle and Pierre-Simon Laplace. In 1967, a physicist named John Archibald Wheeler came up with the name “black hole". Studying black holes can tell us many things about our galaxy and help scientists answer questions about the universe.

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