Companion planting is the idea that some kind...

Companion planting is the idea that some kinds of plants can help each other grow. Plants that are compatible（兼容的，能共处的） together generally have similar needs in terms of nutrients，soil and moisture levels.

Advice about which plants are compatible is sometimes based more on tradition than proof. But experts say there is evidence to support certain combinations. These can improve harvests，reduce disease and help with pest control by attracting helpful insects.

For example，some kinds of soil bacteria take nitrogen from the air and make it into a form that plants can use. The plants hold the nitrogen in their roots. Legumes(豆科植物)are especially good at this nitrogen(氮)fixing. Then any crops that share the same space with the legumes can get the nitrogen when the roots are broken down.

Beans and potatoes can also share territory well because their roots reach different levels in the soil. Deep-rooted vegetables get nutrients and moisture from lower down in the soil，so they do not complete with plants with shallower roots.

But some plants placed together may harm each other's development. For example，tomatoes do not like wet soil but watercress does，so you would probably want to keep them separated.

Some kinds of produce should be kept apart even after being harvested. This is because of ethylene gas(乙烯气体)．Ethylene is a plant hormone(激素)that can cause some foods to ripen too quickly. Apples release ethylene gas. Apricots，melons and tomatoes also release a lot of ethylene. Some vegetables are easily affected by ethylene，including asparagus，broccoli，cabbage and cucumbers.

This risk of ripening too soon is why markets often separate high ethylene-producing foods from those that are sensitive to the gas. But if you put an apple in a bag with a green banana，the ethylene from the apple will make the banana ready to eat sooner.

What about peaches，plums and nectarines? These kinds of fruit do not need any help from an apple—they release enough ethylene to ripen themselves. But that does not mean there is no way to get the job done faster.

Growers suggest placing the fruit in a fruit bowl or in a paper bag with the top folded over. Keep the fruit at room temperature，out of direct sunlight. Once the fruit is soft enough，either use it or put it in the refrigerator to keep it from getting too ripe.

1.Companion planting refers to the idea that 　　　　　 ．

A. some crops can grow together to benefit each other

B. some crops have the similar needs of nutrients，soil and water level

C. some plants can damage each other if grown together

D. a good farming method to prevent natural disasters

2.According to the text，　　　　　 cannot grow together.

A. beans and potatoes B. tomatoes and watercress

C. legumes and corns D. rice and sugarcane

3.What is the function of ethylene?

A. To improve the quality of fruits. B. To produce a poisonous gas.

C. To keep vegetables fresh. D. To make fruits ripe earlier.

4.The text is most likely to be taken from　　　　　 ．

A. a newspaper of medicine B. a magazine of biology

C. a journal of agriculture D. a travel report

高二英语阅读理解中等难度题查看答案及解析

A new report said that different types of plants can release some chemical into the air to help other plants. These chemical warnings all have the same purpose — to spread information about one plant's disease or infestation so other plants can defend themselves. But exactly how plants receive and act on many of these signals is still mysterious.

In this week’s Proceedings of the National Academy of Sciences, researchers in Japan offered some explanations. They had identified one chemical message and traced it all the way from release to action.

The scientists looked at tomato plants infested by a common pest, the cutworm. The researchers studied leaves from exposed and unexposed plants. They found one compound showed up more often in the exposed plants. The substance is called Hex Vic. When the scientists fed Hex Vic to cutworms, it knocked down their survival rate by 17%. The scientists identified the source of Hex Vic, and sprayed it lightly over healthy plants. Those plants were then able to start producing the cutworm-killing Hex Vic. Researchers confirmed that uninfected plants have to build their own weapons to fight off bugs and disease. How do they know when to play defense? They are warned first by their friendly plant neighbors.

It is a complex tale, and it may be happening in more plant species than tomatoes. It may also be happening with more chemical signals that are still unknown to us. Further studies are needed to increase agricultural efficiency.

1.Which is the way used by plants to warn their neighbors?

A. Using of winds.

B. Identifying the chemicals.

C. Releasing some chemicals.

D. Being exposed early.

2.It can be inferred from the text that ________.

A. farmers may benefit from the further studies

B. the phenomenon may be happening in less plant species than tomatoes

C. there are not chemical signals

D. plants are warned first by their neighbors

3.What’s the function of Hex Vic?

A. It sprays over healthy plants.

B. It shows up more.

C. It cures the disease.

D. It damages the cutworm’s body.

4.The passage is likely to appear in ________.

A. a newspaper advertisement

B. a physics textbook

C. a science magazine

D. a finance report

高二英语阅读理解中等难度题查看答案及解析

That kind of plant can be made ______ paper and paper can be made ______ wood.

A. of; of      B. from; of     C. from; into     D. into; from

高二英语单项填空中等难度题查看答案及解析

It’s said that this kind of plant only gives off this strange perfume on ________ conditions which the scientists are trying to figure out now.

A. outstanding        B. certain            C. obvious         D. ordinary

高二英语单项填空简单题查看答案及解析

1.Sunshine is good for the g________________ of plants.

2.Many drugs can be physically and m________________ dangerous.

3.The climb to the top of the mountain left the weak boy b________________.

4.Her a________________ of mind during driving nearly caused an accident.

5.These stores sell all brands of 3G mobiles which v________________ from Samsung to Nokia.

6.The judge found her g________________ of murder and sentenced her to death.

7.Those who i________________ provide teenagers with drugs will be severely punished.

8.Students from different schools sat together e________________ ideas about how to protect the environment.

9.Jack was infected with AIDS and he had only a small chance of s__________________.

10.The crowd p________________ at the sound of the guns and ran in all directions.

高二英语单词拼写中等难度题查看答案及解析

阅读填空

We have all kinds of festivals. Ancient people held festivals to 1. the end of winter, planting in spring and harvest in autumn. Today’s festivals have many 2. : some are 3., some seasonal and some for special people or events.

Some festivals are in memory of the dead or to satisfy the 4.. 0n the important feast day in Mexico, besides 5. food, flowers and gifts to the dead, people eat food in the shape of skull and cakes with “bones” on them

People hold festivals as an honor to famous people, like the Dragon Boat Festival which honors the famous 6. , Qu Yuan.

Harvest and Thanksgiving festivals are held in many countries. In European countries, some people might win 7. for their farm produce in competitions. On Mid-Autumn festivals in China and some Asian countries, people 8. the moon and have moon cakes.

Chinese New Year is one of the most 9. and important festivals. People look forward to eating dumplings, giving lucky money in red paper and playing dragon dances.

To sum up, festivals let us enjoy life, be proud of our 10. and forget our work for a little while.

高二英语根据课文内容填空中等难度题查看答案及解析

Some plants get so hungry they eat flies, spiders, and even small frogs. What’s more amazing is that these plants occur naturally (in special environment) in every state. In fact, they’re found on every continent except Antarctica.

You’ve probably seen a Venus’ flytrap. It’s often sold in museum gift stores, department stores, and even supermarkets. A small plant, it grows 6 to 8 inches tall in a container. At the end of its stalks（茎）are specially modified leaves that act like traps. Inside each trap is a lining of tiny trigger(触发) hairs. When an insect lands on them, the trap suddenly shut. Over the course of a week or so, the plant feeds on its catch.

The Venus’ flytrap is just one of more than 500 species of meat-eating plants, says Barry Meyers-Rice, the editor of the International Carnivorous Plant Society’s Newsletter. Note: Despite any science –fiction stories you might have read, no meat-eating plant does any danger to humans.

Dr. Meyers-Rice says a plant is meat-eating, only if it does all four of the following: “attract, kill, digest, and absorb” some forms of insects, including flies, butterflies, and moths. Meat-eating plants look and act like other green plants ---well, most of the time.

All green plants make sugar through a process called photosynthesis(光合作用). Plants use the sugar to make food. What makes “meat-eating” plants different is their bug-catching leaves. They need insects for one reason: nitrogen(氮). Nitrogen is a nutrient that they can’t obtain any other way. Why almost all green plants on our planet get nitrogen from the soil “Meat-eating” plants can’t. They live in places where nutrients are hard or almost impossible to get from the soil because of its acidity(酸度). So they’ve come to rely on getting nitrogen from insects and small animals. In fact, nutrient-rich soil is poisonous to “meat-eating” plants. Never fertilize(施肥)them! But don’t worry, either, if they never seem to catch any insects. They can survive, but they’ll grow very slowly.

1.According to the passage, carnivorous plants________ .

2.Venus’ flytrap preys on insects by ________ .

3.We can conclude from the third paragraph that_____.

4.In the eyes of the author, which of the following statements is TRUE?

高二英语阅读理解中等难度题查看答案及解析

Dodder is an unusual and unwanted plant that attacks other plants. Except for its flowers, the plant looks like spaghetti, a kind of noodles in the shape of long thin pieces that look like string when they are cooked. Its almost leafless, thread-like stems（茎）hang down on top of other plants that dodder needs to stay alive. Dodder does not produce its own food. Instead, it steals food from other plants. It feeds by sucking juices from the plant which is wrapped around, often making its host very weak or even killing it.

Dodder can find other plants by their smell. When a young dodder plant starts growing, it follows the smell of plants it prefers, like tomato plants, potato plants, or other farm crops. Unlike most plants that usually grow in the direction of light or warmth, a dodder plant will grow in the direction of, for example, tomato smell-if a tomato happens to be growing nearby.

However, a young dodder plant must find a host plant quickly. It no longer needs its root once it is attached to the host and wrapped around it. If it cannot catch a smell of a potential host within a few days, it will dry up and disappear-even if there is plenty of water around. Once it finds a host, the young dodder plant will attach itself to it and start growing faster. At that point the dodder plant will drop its root.

Dodder is thus a difficult weed to manage and a real headache for farmers. When it does get out of hand, dodder can greatly reduce a farmer’s harvest or even destroy crops completely. Before sowing their produce, especially farmers in warm parts of the world often check to make sure no unwanted dodder seeds have mixed with their crop seeds. This is a good way to stop dodder plants from making their way to a crop field secretly.

1.Why does the author mention spaghetti in the first paragraph?

A. To analyze the content of some food.

B. To describe tie shape of dodder plants.

C. To explain where the dodder plants come from.

D. To argue that dodder plants can be used.

2.What will happen if a dodder plant starts growing where there are no other plants around?

A. It will die sooner or later.

B. It will grow deep roots.

C. It will attract other plants.

D. It will cover the entire area of soil.

3.What can be inferred from the passage?

A. Dodder does not produce its own food.

B. Dodder can affect farmers’ income.

C. Dodder can only survive in the shade.

D. Dodder only grows in the warm areas.

4.What is the main topic of the passage?

A. A new variety of farm crops.

B. Plants that are harmful to humans.

C. The special abilities of a dangerous plant.

D. Recent improvements in farming methods.

高二英语阅读理解中等难度题查看答案及解析

Some of the planet’s most precious animals and plants are disappearing, according to the World Conservation Union (IUCN). The group, based in Switzerland, works with governments and experts to protect threatened species. On September 12, the IUCN released its Red List, a list of species at greatest risk of extinction.

The list includes 41,415 animals and plants. The IUCN says that habitat destruction, hunting and other causes threaten one in four mammals, one in eight birds and one in three amphibians(两栖动物).

Who is to blame?

Scientists believe that 99 percent of threatened species are at risk because of human activity. “We are losing animals and plants at a high rate,” says Julia Marton-LefEevre, director general of the IUCN. “We need to change our behavior.” Warmer oceans and over-fishing are changing sea life. This year for the first time corals(珊瑚) made their appearance on the list. The gharial, a crocodile living in India and Nepal, has lost almost 60 percent of its population in the last 10 years. It is a victim（受害者）of habitat destruction.

Still, the news is not all bad. Thanks to efforts made to protect it, the Mauritius echo parakeet, a bird once endangered, has seen an increase in its population. “This shows that protection methods can work,” says Marton-LefEevre. “That’s the message we want to send to young people.”

In China the new reserve（保护区）itself is part of green efforts that have seen more than 2,400 nature reserves of various kinds being set up, covering more than 15 percent of the nation's land area, official figures showed.

"The country's natural resources(资源) have benefited from conservation," said Lei Guangchun, director of the nature reserve department of Beijing Forestry University. "It is a big increase nowadays compared with other countries." Lei said.

The total areas of China’s natural reserves have covered 1.38 million km2, which accounts for 15.4% of China’s area, higher than both the world average（平均水平） of 11% and the rate in most developed countries.

Li Zhong, an official in charge of the nature reserves office with the State Forestry Administration, thought it was important to increase investment（投资） in such reserves at all levels.

1.What do we know about the IUCN?

A. A union for listing animals and plants on the earth

B. A group of volunteers who are interested in wildlife

C. An organization concerning the protection of rare species' survival

D. A government made up officials, scientists and experts

2.What can be concluded from the passage?

A. All the protection methods can’t work.   　

B. The IUCN does most of the protection.

C. The efforts China makes has paid off.　

D. Enough is done in wildlife protection.

3. Which of the following is not the cause of the disappearance of the animals?

A. Bad weather     B. Over-hunting    C. Warmer oceans    D. Habitat destruction

4.Which of the sentence is NOT true?

A. China has been paying great attention to protecting the natural resources.

B. China has set up a lot of natural reserves.

C. The natural reserves in China cover more than 15 percent of the nation's land area.

D. The rate of China's natural reserves is lower than the average of the world.

高二英语阅读理解简单题查看答案及解析

Recently, some concerns have been raised about the health of the world's banana plants. Many media reports have said that bananas may completely disappear in the coming ten years.

Bananas are one of the world's most important food crops. They are also the fourth most valuable export. Bananas do not grow from seeds. Instead, they grow from existing plants. Bananas are threatened by disease because all the plants on a farm are copies of each other. They all share the same genetic weaknesses.

For example, the Cavendish banana is most popular in American markets. It is an important export crop. However, some kinds of fungus (真菌) organisms easily infect the Cavendish. Black Sigatoka disease affects the leaves of Cavendish banana plants. The disease is controlled on large farms by putting chemicals on the plant's leaves. Farmers put anti-fungal chemicals on their crops up to once a week.

Another fungal disease is more serious. Panama disease attacks the roots of the banana plant. There is no chemical treatment for this disease. Infected plants must be destroyed. Panama disease has affected crops in Southeast Asia, Australia and South Africa. There is concern that it may spread to bananas grown in the Americas. This could threaten an important export product for Central and South America.

The International Network for the Improvement of Banana and Plantain, whose headquarter lies in France, supports research on bananas. The group says that more research must be done to develop improved kinds of bananas.

The group says that fungal diseases mainly affect only one kind of banana. In fact, there are five-hundred different kinds of bananas. The United Nations Food and Agriculture Organization says the Cavendish banana represents only ten percent of world production.

The UN agency says farmers should grow different kinds of bananas. This protects against diseases that affect only one kind. Experts warn that disease may cause the Cavendish banana to disappear. This has already happened to one popular banana because of its genetic weakness against disease. (words: 335)

1.What does the passage mainly tell us?

A．Bananas are the world’s most important food crops.

B．There are five hundred different kinds of bananas.

C．The risk to a popular banana shows need to grow other kinds.

D．How to grow bananas in different countries.

2.Bananas are threatened by diseases because ___­­­­­­_______.

A．they have genetic weaknesses against disease.

B．they are one of the most valuable exports.

C．the only way to prevent it is to put chemicals on their leaves.

D．they grow from the seed

3.Panama disease__________.

A．doesn’t belong to fungal disease.

B．has spread to bananas in the world.

C．affects the leaves of banana plants.

D．destroys the bananas more seriously than Black Sigatoka disease.

4.We can infer from Paragraph 6 that ____________.

A．the center of the group is in the US.

B．the key to solving the disease is to research all kinds of bananas.

C．the Cavendish banana covers only a small part of the output of bananas.

D．each fungal disease affects five hundred different kinds of bananas.

5.According to the passage, which information is right?

A．The Cavendish banana can be mainly imported from North America and Europe.

B．Fungal diseases mainly affect the Cavendish banana.

C．The Cavendish banana won’t die out in the future.

D．Panama disease affects the leaves of banana plants.

高二英语阅读理解中等难度题查看答案及解析