Soil conservation efforts protect soil from wind and water that can blow or wash it away. Good soil produces food crops for both people and animals.
One important form of soil conservation is the use of windbreaks (防風(fēng)林). Windbreaks are barriers formed by trees and other plants with many leaves. Farmers plant them in lines around their fields. Windbreaks stop the wind from blowing soil away. They also keep the wind from destroying or damaging crops. They are very important for growing grains, such as wheat.
For example, in parts of West Africa, studies have shown that grain harvests can be twenty percent higher on fields protected by windbreaks compared to those without such protection.
Windbreaks are effective when a wall of trees and other plants blocks the wind. The windbreaks should also limit violent motions of the wind to those areas closest to the windbreak.
However, windbreaks seem to work best when they allow a little wind to pass through. If the wall of trees and plants stops wind completely, then violent air motions will take place close to the ground. These motions cause the soil to lift up into the air where it will be blown away. For this reason, a windbreak is best if it has only sixty to eighty percent of the trees and plants needed to make a solid line.
An easy rule to remember is that windbreaks can protect areas up to ten times the height of the tallest trees in the windbreak.
There should be at least two lines in each windbreak.One line should be large trees.The second line, right next to it, can be shorter trees and other plants with leaves.
Windbreaks not only protect land and crops from the wind.They can also provide wood products. These include wood for fuel and longer pieces for making fences.Locally-grown trees and plants are best for windbreaks.
1.What does this text primarily concern?
A.A way to protect soil.
B.Some advice on growing windbreaks.
C.The effect of windbreaks.
D.A way to protect crops.
2.Which of the following is NOT true about windbreaks?
A.If windbreaks stop the wind completely,the soil will be blown away above the windbreaks.
B.Leaving sixty to eighty percent of the trees and plants needed to make a solid line is a best windbreak.
C.A better windbreak should be two lines or more with the same height.
D.Windbreaks work best during an area up to ten times the height of the tallest trees in them.
3.The underlined word "barriers" (Para.2) refers to .
A.something that is built with trees together with other plants.
B.a(chǎn) structure built to forbid passage of wind with trees or other plants.
C.something used to help things control their movement.
D.narrow lines where trees and other plants with many leaves are planted.
4.Which of the following is most likely to show the right area that a windbreak can protect?
年級(jí) | 高中課程 | 年級(jí) | 初中課程 |
高一 | 高一免費(fèi)課程推薦! | 初一 | 初一免費(fèi)課程推薦! |
高二 | 高二免費(fèi)課程推薦! | 初二 | 初二免費(fèi)課程推薦! |
高三 | 高三免費(fèi)課程推薦! | 初三 | 初三免費(fèi)課程推薦! |
科目:高中英語(yǔ) 來源:福建省仙游縣金石中學(xué)高一下學(xué)期unit13-unit15單元測(cè)試 題型:閱讀理解
B
All of us eat every day, but most of us don’t understand nutrition. We often make mistakes in talking about good diet.
For example, many people think that foods such as rice, bread and potatoes will make one grow fat. In fact, these foods are very good to one’s health. They are good sources of many vitamins. And in comparison with steak and beef, they contain less amount of calories.
Some people don’t like canned(罐裝的) or frozen vegetables, because they think fresh vegetables cooked at home are always better. This is again wrong. In fact, whether the vegetables are good or not depends more on how they are prepared. Overcooking, for example, destroys good qualities of vegetables. Vegetables cooked in too much water can use a large amount of vitamins.
It is widely believed extra vitamins provide more energy. But taking more than the body needs doesn’t make it function better.
It is also wrong to say that vegetables grown in poor, worn-out soil are lower in vitamins than vegetables grown in rich soil. The vitamins in our foods are in the plants themselves. They don’t come from the soil. However, the minerals(礦物質(zhì)) in a plant depend on the minerals in the soil.
In short, there are many false ideas about nutrition. We need to correct them.
1. This passage is mainly about_______.
A. nutrition B. vitamins C. vegetables D. health
2. Rice, bread and potatoes do good to people’s health mainly because_______.
A. they make people fat B. there are lot of vitamins in them
C. they contain less amount of calories compared with steak and beef.
D. both B and C.
3. Why don’t some people like canned or frozen vegetables? Because______.
A. they think fresh vegetables contain less vitamins
B. they think fresh vegetables contain more vitamins than the canned or frozen ones
C. they don’t think the canned or frozen vegetables are fresh
D. they don’t think the canned or frozen vegetables taste as good as the fresh ones
4. Which of the following is true according to the passage?
A. Many people know almost everything about nutrition.
B. Food such as rice, bread and potatoes make people fat.
C. vegetables grown in poor worn-out soil may have the same amount of vitamins as vegetables grown in rich soil.
D. extra vitamins provide less energy.
5. The point of the passage is that______.
A. the minerals in a plant depend on the minerals in the soil
B. people make mistakes when talking about good diet
C. taking more vitamins than the body needs doesn’t make it function better
D. vegetables cooked in too much water can lose a large amount of vitamins
查看答案和解析>>
科目:高中英語(yǔ) 來源:2012-2013屆山東省淄博市博山實(shí)驗(yàn)中學(xué)高三12月月考英語(yǔ)試卷(帶解析) 題型:閱讀理解
"It's this time of year when the weather starts warming up and frogs start breeding - but they haven't been breeding," says John Wilkinson, research and monitoring officer at the Amphibian and Reptile Conservation Trust (ARC).
Amphibians (兩棲動(dòng)物) are just one of the groups of animals that nature observers fear may have problems reproducing this year, as groundwater levels are even lower now than in the infamously dry summer of 1976, according to the Department for Environment, Food and Rural Affairs (Defra). According to the UK's Centre for Hydrology and Ecology the average rainfall so far this winter has been the lowest since 1972.
"If ponds dry up totally," says Mr. Wilkinson, "you could have lots of dead tadpoles." Drier and windier conditions could also make it more difficult for juvenile amphibians to survive their journeys between wet habitats.
But Peter Brotherton, the biodiversity manager for Natural England, says that "drought is part of nature's cycle", and, at present, a lot of animals, plants and insects are still in hibernation. This means that the population picture is unclear. "However, when we get extreme events, we get animals dying," he says. "And what is worrying is that normally at this time of year we expect soil to be near saturation(濕潤(rùn))after winter."
Charlie Kitchin, the RSPB's site manager of the Nene Washes in Cambridgeshire, says the 2,000-acre wetland and grassland area is now struggling following two winters with relatively little winter rain and no flooding. One species that could suffer, he says, is the black-tailed godwit(黑尾豫). "There are only 50 breeding pairs in the country, and we have 40 of them, and everything is bone-dry," Mr Kitchin says.
But one bad nesting season, he says, is "not the end of the world". "One of the features of flood plains is that they're volatile anyway," he adds. "But if they fail to breed another year, the population is likely to dip again."
【小題1】According to the passage animals may have problems reproducing this year mainly due to _____.
A.drought | B.hibernation | C.windier conditions | D.extreme events |
A.drought is part of nature’s cycle | B.a(chǎn)nimals are still in hibernation |
C.soil at this time is far from saturation | D.the population of animals is still unclear |
A.Drought has so far continued for two winters. |
B.Animals could survive one bad nesting season. |
C.The black-tailed godwit is in danger of extinction. |
D.40 black-tailed godwits live in the Nene Washes. |
A.losing water | B.undergoing changes |
C.breeding animals | D.suffering flood |
A.groundwater levels this summer are lower than those of 1976 |
B.the average rainfall this year has been the lowest since 1972 |
C.windier conditions could also cause some amphibians’ death |
D.flooding plays no useful role in wetlands and grasslands |
查看答案和解析>>
科目:高中英語(yǔ) 來源:2015屆河北省石家莊市高二上學(xué)期期中考試英語(yǔ)試卷(解析版) 題型:閱讀理解
Most kinds of rose plants come from Asia. But roses are also native to other areas including northwest Africa, Europe and the United States. In 1986, Congress chose the rose as America’s national flower. Technically, Congress and President Ronald Reagan declared it the “national floral emblem.” Whatever the name, the decision did not smell sweet to supporters of others popular flowers.
Some people say roses are difficult to grow. But you have a good chance of success if you start with a few suggestions from experts. You should plant your roses where they can get sunshine for about six hours on bright days. You can buy roses form a garden center or by mail order. You can buy potted roses, also known as container roses, or bare-root plants. Each kind has its fans.
Some gardeners say potted roses are easier to plant. They say the roots develop better. But Jeffrey Dinslage, an expert, pint out that bare-root roses come without soil. So they weigh less to transport.
Another expert advises getting bare-foot roses as close to planting time as you can. If they arrive before you are ready to plant them, make sure the packing material is moist. Keep the plants in a cool, dark place. The resting plants have no leaves but still need water. When growing roses, the soil should feel moist deep down. Watering should be done in the morning.
But do not water too much. People often ask Jeffrey Dinslage about unhealthy discoloration on rose leaves. He says the spots are usually caused by too much water. After heavy rains or too much watering, he advises pulling away mulch, the substance used to protect the roots, temporarily from around the roots. This will help dry the soil.
1.From the first paragraph, we know that in the United States _______.
A. all the people like roses B. there are a lot of national flowers
C. some roses don’t smell sweet D. there are some other popular flowers
2.Why does Jeffrey Dinslage suggest planting bare-root roses?
A. They are easier to plant. B. Their roots develop better.
C. They are cheap to transport D. Their leaves need no water
3.Which of following is closest in meaning to the underlined word “moist”?
A. Slightly wet. B. Pretty dry. C. Too hard. D. Lightly soft.
4.According to Jeffrey Dinslage, people should ______ to avoid the spots on the rose leaves.
A. not water roses in the morning B. protect the roots of roses
C. improve the quality of the soil D. not water roses very much
查看答案和解析>>
科目:高中英語(yǔ) 來源:2015屆安徽省高二上學(xué)期期中考試英語(yǔ)試卷(解析版) 題型:單項(xiàng)填空
This also keeps the air,soil,water crops________ chemicals.
A.out of B.out from C.free of D.rid of
查看答案和解析>>
科目:高中英語(yǔ) 來源:2012-2013學(xué)年貴州省高三上學(xué)期期末考試英語(yǔ)試卷(解析版) 題型:閱讀理解
At least 10 million hectares of cultivated(耕作)land in China are polluted, which makes a grave threat to the country’s food safety, the Xinhua News Agency reported on Friday.
The polluted land,which is mostly in economically developed areas,accounts for one-tenth of the country’s total arable(可耕種的)land,according to an incomplete survey by the State Environmental Protection Administration,China’s top environment watchdog.
Pollution on cultivated land threatens the environment,food safety and the sustainable development of agriculture,the administration said.
Because of continual,too much use of chemical fertilizer, pesticide and agricultural plastic sheeting, as well as irrigation using polluted water, a large amount of contaminants(污染物)remain in the cultivated land.
The contaminants affect the soil’s ecological structure and function,leading to decreased soil productivity, lower crop yield(產(chǎn)量),and lower quality of agricultural products-
It also leads to worse water quality in rural areas.
Less than 9 per cent of drinkable water passed checks for bacteria in243 rural water supply stations across the county.
Another survey, which took samples of drinking water and groundwater an 69 small towns。 in Beijing, Tianjin and Hebei Province of North,China, showed that more than half of the water contains too much nitrate(硝酸鹽),which may cause diabetes(糖尿。゛nd damage the kidney.
The administration estimated at least 1 90 million farmers are drinking water that contains harmful substances.
Many villagers drink unfiltered water taken from shallow water wells or water cellars, which are reported to have poor sanitary conditions·
1.The author writes the passage to .
A.1et the readers examine their mistakes
B.present the readers a new idea
C.come up with a solution to ending farmland pollution
D.inform the readers of the importance of fighting farmland pollution
2.The underlined word “grave” in Paragraph 1 probably means
A.serious B.certain C.big D.terrible
3.Pollution on cultivated land leads to the following outcomes EXCEPT .
A.a(chǎn) threat to China’s food safety
B.worse water quality in rural areas
C.a(chǎn) variety of diseases
D.the sustainable development of agriculture
查看答案和解析>>
百度致信 - 練習(xí)冊(cè)列表 - 試題列表
湖北省互聯(lián)網(wǎng)違法和不良信息舉報(bào)平臺(tái) | 網(wǎng)上有害信息舉報(bào)專區(qū) | 電信詐騙舉報(bào)專區(qū) | 涉歷史虛無(wú)主義有害信息舉報(bào)專區(qū) | 涉企侵權(quán)舉報(bào)專區(qū)
違法和不良信息舉報(bào)電話:027-86699610 舉報(bào)郵箱:58377363@163.com