Against the supposition that forest fires in Alaska,Canada and Siberia warm the climate,scientists have discovered that cooling may occur in areas where burnt trees allow more snow to mirror more sunlight into space.
This finding suggests that taking steps to prevent northern forest fires to limit the release of greenhouse gases may warm the climate in northern regions.Usually large fires destroyed forests in these areas over the past decade.Scientists predict that with climate warming,fires may occur more frequently over the next several centuries as a result of a longer fire season.Sunlight taken in by the earth tends to cause warming,while heat mirrored back into space tends to cause cooling.
This is the first study to analyze all aspects of how northern fires influence climate.Earlier studies by other scientists had suggested that fires in northern regions sped up climate warming because greenhouse gases from burning trees and plants were released into the atmosphere and thus trapped heat.
Scientists found that right after the fire,large amounts of greenhouse gases entered the atmosphere and caused warming.Ozone (臭氧) levels increased,and ashes from the fire fell on far­off sea ice,darkening the surface and causing more radiation from the sun to be taken in.The following spring,however,the land within the area of the fire was brighter than before the fire,because fewer trees covered the ground.Snow on the ground mirrored more sunlight back into space,leading to cooling.
“We need to find out all possible ways to reduce the growth of greenhouse gases in the atmosphere,” scientists said.They tracked the change in the amount of radiation entering and leaving the climate system as a result of the fire,and found a measurement closely related to the global air temperature.Typically,fire in northern regions occurs in the same area every 80 to 150 years.Scientists,however,found that when fire occurs more frequently,more radiation is lost from the earth and cooling results.Specifically,they determined when fire returns 20 years earlier than predicted,0.5 watts per square meter of area burned are soaked up by the earth from greenhouse gases,but 0.9 watts per square meter will be sent back into space.The net effect is cooling.Watts are used to measure the rate at which energy is gained or lost from the earth.
小題1:According to the new findings,taking steps to prevent northern forest fires may________.
A.result in a warming climate
B.cause more forest fires
C.lead to a longer fire season
D.protect the forests there
小題2:The following are the immediate effects after a forest fire EXCEPT________.
A.large amounts of greenhouse gases enter the atmosphere
B.the levels of ozone which is a type of oxygen increase
C.snow on the ground mirrors more sunlight back into space
D.a(chǎn)shes from the fire fall on the ice and darken the surface
小題3:Earlier studies about northern forest fires________.
A.had analyzed all aspects of how northern fires influenced climate
B.had indicated that forest fires would pollute the atmosphere
C.had suggested that people should take measures to protect environment
D.had suggested that the fires would speed up climate warming
小題4:We can infer that forest fires in Alaska,Canada and Siberia may________.
A.warm the climate as the supposition goes
B.cool the climate by reflecting more sunlight into atmosphere
C.make more space for the growth of young trees
D.help to gain more energy rather than release more energy

小題1:A
小題2:C
小題3:D
小題4:B

小題1: A
解析 細(xì)節(jié)理解題。文章第二段第一句說,為了限制溫室氣體的排放而采取措施預(yù)防北方森林大火,反而會(huì)導(dǎo)致北方地區(qū)氣候變暖。因此A項(xiàng)正確。B項(xiàng)和C項(xiàng)都是由氣候變暖引起的;D項(xiàng)在文中并未說明。
小題2:C
解析 細(xì)節(jié)理解題。由文章第四段前兩句可知,火災(zāi)發(fā)生后,大量的溫室氣體進(jìn)入大氣層,臭氧增多,灰燼落到遠(yuǎn)方的冰山上,把冰面弄黑。這都是發(fā)生火災(zāi)后會(huì)立即出現(xiàn)的情況。由第四段最后兩句可知,地面上的雪折射更多的太陽(yáng)光返回大氣層,在第二年的春天才會(huì)發(fā)生,故選C項(xiàng)。
小題3: D
解析 細(xì)節(jié)理解題。由文章第三段第二句可知D項(xiàng)正確。
小題4: B
解析 推理判斷題。由文章第一段和第四段的具體分析可知,北方的森林大火能使地面上的雪向大氣折射回更多的陽(yáng)光,以此達(dá)到降低氣溫的效果。
練習(xí)冊(cè)系列答案
相關(guān)習(xí)題

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

Businesses are witnessing a difficult time,which has in turn produced influence on consumers’ desire to go green.However,shoppers are still laying stress on environmental concerns.
Two thirds of customers say that environmental considerations inform their purchases to the same degree as they did a year ago,while more than a quarter say that they are now even better aware of the environmental effect on what they buy.
This may help to influence how shops store goods on their shelves.And the companies should still make efforts to become more environmentally friendly.Two out of three people think it is important to buy from environmentally responsible companies,with about one in seven saying that they had even decided to take their custom elsewhere if they felt a company’s environmental reputation was not good enough.
Harry Morrison,chief executive(主管)of the Carbon Trust,sympathizes:“I understand this situation where survival is very important now.But from environmental considerations,the clock is ticking—we don’t have much time.In addition,cutting carbon has an immediate effect as costs drop and a medium­term benefit for the brand.”
Larger companies have an extra motivation to look at reducing their carbon footprint,as new rules next year will require businesses to buy carbon allowances to make up for their emissions(排放).Those that have taken early action will have a head start.More than two thirds of consumers are not clear about which companies are environmentally responsible.This suggests that firms that are able to relay clearly their message to the public will be in a pole position to attract shoppers.
The Carbon Trust believes that it can help by informing customers about the good work companies are doing.“When companies are granted(授予) the standard,they can use a logo(標(biāo)識(shí)) in all their marketing which makes it clear that they are working towards cutting emissions,” Mr.Morrison said.                                                  (2010·福建,C)
小題1:What’s the main idea of the passage?
A.Businesses are finding ways to send their message to the shoppers.
B.Companies will soon get information about cutting carbon emissions.
C.Firms are making efforts to encourage customers to keep goods at home.
D.Firms are urged to cut carbon emissions by shoppers’ environmental awareness.
小題2:The underlined word “inform” in Paragraph 2 probably means “________”.
A.a(chǎn)ffectB.changeC.disturbD.reject
小題3:According to Harry Morrison,businesses ________.
A.will benefit from cutting carbon emissions
B.should buy carbon allowances for shoppers
C.a(chǎn)re required to make up for their carbon emissions
D.have encouraged shoppers to take their custom elsewhere
小題4:We can learn from the passage that businesses will________.
A.have a strong desire to reduce costs
B.use the same logo in their marketing
C.gain advantages by taking early action
D.a(chǎn)ttract more shoppers by storing goods

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

LONDON—Here’s a new warning from health experts:Sitting is deadly.
Scientists are increasingly warning that sitting for long periods—even if you also exercise regularly—could be bad for your health.And it doesn’t matter where the sitting takes place—at the office,at school,in the car or before a computer or TV—just the overall number of hours it occurs.Several studies suggest people who spend most of their days sitting are more likely to be fat,have a heart attack or even die.
In an editorial published this week in the British Journal of Sports Medicine,Elin Ekblom­Bak of the Swedish School of Sport and Health Sciences suggested that authorities rethink how they define physical activity to highlight the dangers of sitting.
While health officials have issued guidelines recommending minimum amounts of physical activity,they haven’t suggested people try to limit how much time they spend in a seated position.
“After four hours of sitting,the body starts to send harmful signals,”said Ekblom­Bak.She explained that genes regulating(調(diào)節(jié)) the amount of glucose(葡萄糖) and fat in the body start to shut down.
Even for people who exercise,spending long periods of time sitting at a desk is still harmful.Tim Armstrong,a physical activity expert at the World Health Organization,said people who exercise every day—but still spend a lot of time sitting—might get more benefit if that exercise was spread across the day,rather than in a single bout(一回).
Still,in a study published in 2009 that tracked more than 17,000 Canadians for about a dozen years,researchers found people who sat more had a higher death risk,whether or not they exercised.
“We don’t have enough evidence yet to say how much sitting is bad,” said Peter Katzmarzyk of the Pennington Biomedical Research Center in Baton Rouge,who led the Canadian study.“But it seems the more you can get up and interrupt this sedentary behavior,the better.”
Figures from a U.S. survey in 2003­2004 found Americans spend more than half their time sitting,from working at their desks to sitting in cars.
Experts said more research is needed to figure out just how much sitting is dangerous,and what might be possible to offset those effects.
“People should keep exercising because that has a lot of benefits,” Ekblom­Bak said.“But when they’re in the office,they should try to interrupt sitting as often as possible,” she said.
小題1:What is the best title for the text?
A.Not Sitting Too Much While Working
B.How to Avoid Sitting Too Much
C.Sitting Too Much Could Be Deadly
D.More and More People Sit Too Much
小題2:According to the research,________.
A.the more time you spend in exercising in a single bout(一回),the healthier you will be
B.those who often sit too much are sure to grow fat or suffer from a heart attack
C.regular exercise is effective to get rid of the side effects of sitting too much
D.you had better not sit for more than four hours in a single bout
小題3:How does the danger of sitting too much affect the human body?
A.It results in a higher death risk.
B.It increases glucose and fat in the body.
C.It makes a person unable to exercise long enough in a day.
D.It causes the gene to fail to balance the glucose and fat in the body.
小題4:The underlined word “offset” in Paragraph 10 most probably means “________”.
A.improveB.a(chǎn)void
C.ignoreD.a(chǎn)chieve

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

Plastic is one of the most important technological discoveries of the 20th century.However,it may soon be replaced.The new development—liquid wood—can replace plastics in all branches of modern industries.
Plastic as a material enjoys the biggest demand in the modern world,but it does have a number of drawbacks.First and foremost,plastic isn’t recyclable.Secondly,it contains toxins (毒物) helping develop cancerous diseases.Finally,it’s made of oil and oil reserves aren’t endless.
The  liquid wood technology is likely to replace plastic and provide mankind with new materials for many years ahead.Norbert Eisenfreich,a senior researcher at  the Faunhofer Institute for Chemical Technology (ICT) in Germany,said that arboform,the new material,is made of lignin (木質(zhì)素),which can be obtained from soft tissues of wood.Once mixed with several other materials,it turns into solid and non­toxic alternative for plastics.
ICT team leader Emilia Regina Inone­Kauffmann said the wood­working industry separates wood into three basic components,including lignin.Lignin isn’t used for the production of paper.Specialists of ICT mixed lignin with several natural materials and thus invented the material which could be melted and molded (鑄型).
When solid,arboform looks like plastic and possesses the qualities of polished wood.It can be used for the production of any items.Arboform is already used for the production of car parts which require extra strength.In addition,liquid wood can be recycled repeatedly.The material preserved all of its qualities even if it’s reprocessed ten times.
However,the new invention doesn’t enjoy an extensive use due to the high content of sulphur (硫) in it.German researchers are sure to reduce the amount of sulphur by 90 percent very soon to make arboform usable for home needs.
小題1:According to the passage,plastic________.
A.plays a big role in the modern world
B.helps to protect our environment in some way
C.has been replaced by the newly discovered material
D.helps us to reduce the use of petrol
小題2:What’s the advantage of arboform over plastics?
A.It is easily made from natural oil.
B.It is more widely used in household.
C.It is recyclable and friendly to the environment.
D.It contains no poisonous materials.
小題3:It can be concluded that German researchers will focus their future work firstly on________.
A.the material’s extensive use
B.the content of sulphur in arboform
C.the production cost of arboform
D.the qualities of liquid wood
小題4:The main purpose of the passage is to________.
A.a(chǎn)dvertise the new material—arboform
B.introduce liquid wood which will replace plastic
C.a(chǎn)dvertise new products made of arboform
D.show readers how to produce arboform

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

“It hurts me more than you,’’and “This is for your own good.’’These are the statements my mother used to make years ago when I had to learn Latin,clean my room,stay home and do homework.
That was before we entered the permissive period in educafion in which we decided it was all right not to push our children to achieve their best in school.The schools and the educators made it easy on us.They thought that it was all right to be parents who take a let-alone policy. We stopped making our children do homework. We gave them calculators,turned on the television,left the teaching to the teachers and went on vacation.
Now teachers,faced with children who have been developing at their own pace for the past 15 years,are realizing we’ve made a terrible mistake.One such teacher is Sharon Klompus who says of her students-“so passive”-and-wonders what happened.Nothing was demanded of them,she believes. Television,says Klompus,contributes to children’s passivity.“We’re not training kids to work any more,” says Klompus.“we’re talking about a generation of kids who’ve never been hurt or hungry.They have learned somebody will always do it for them. Instead of saying ‘go look it up’,you tell them the answer.It takes greater energy to say no to a kid.”
Yes,it does.It takes energy and it takes work. It’s time for parents to end their vacation and come back to work.It’s time to take the car away, to turn the TV off, to tell them it hurts you more than them but it's for their own good.It’s time to start telling them no again.
小題1:Why are children becoming more inactive in study?
A.Because they watch TV too often
B.Because they have done too much homework.
C.Because they have to fulfill too many duties.
D.Because teachers are too strict with them.
小題2:To such children as described in the passage         
A.it is easier to say no than to say yes
B.neither is easy-to say yes or to say no
C.it is easier to say yes than to say no
D.neither is difficult-to say yes or to say no
小題3:We learn from the passage that the author’s mother used to lay emphasis on       
A.1earning Latin
B.natural development
C.discipline
D.education at school
小題4:By “permissive period in education’’the author means a time         
A.when children are allowed to do what they wish to
B.when everything can be taught at school
C.when every child can be educated
D.when ehildren are permitted to receive education
小題5:What is the main idea of the passage?
A.Parents should leave their children alone,
B.Kids should have more activities at school.
C.It’s time to be stricter with our kids.
D.Parents should always set a good example to their kids.

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

Will online courses transform world of education?
Some may wonder what it feels like to attend a class at Stanford University. The recently popular MOOCs (Massive Open Online Courses) can satisfy this desire. But they are also most likely to change the situation of higher education. Only last month,both Peking University and Tsinghua University announced plans to start open online course on the edX platform,one of the world’s major providers of MOOCs,to explore this new form of online education.
Gaining momentum(勢(shì)頭)
“It’s not only a change of platforms from offline to online. It’s more about a reform of
teaching methods,even the whole education system,”said Chen Jining,president of Tsinghua University.
The potential of MOOCs to reform education has been obvious in the US ever since the immediate popularity of the course Artificial Intelligence,taught by Stanford University professor Sebastian Thrun, who later co-founded Udacity, a platform with 1.6 million enrolled(注冊(cè)) students in 200 countries. According to Nature magazine,by June 2013,74 percent of universities in the US offered some type of online course. Lu Fang, vice-president of Fudan University,explains the appeal of MOOCs as a simple case of supply and demand:“The demand for high quality educational resources from both enrolled students and professionals is feeding the rise of MOOCs,in which classes usually taught by top teachers are available to everyone,”said Lu.
Too early to replace
With easy access and free of charge, MOOCs are said to have the potential to change the present education system. But there are barriers,because hardly any universities offer degree certificates, as college administrators point out, it’s difficult to confirm if students are foaming anything in MOOCs,reposed USA Today.
The Wall Street Journal also reposed that,presently,a typical MOOC student is likely to have
already graduated from college and is using the course to explore an interest or acquire professional
skills. Even so, an increasing number of undergraduates are signing up.
“What we are really establishing(創(chuàng)建)are educational pathways for people who want skills that are related to contemporary jobs,”Thrun told The Wall Street Journal.
小題1:MOOCs have been considered likely to reform education since___________.
A.the founding of Udacity
B.the wide application of online education
C.the popularity of the course Artificial Intelligence
D.the opening of MOOCs on the edX platform in China
小題2:According to Lu Fang, MOOCs have become popular because___________.
A.high quality educational resources are in demand
B.students can attend courses in famous universities
C.college students have access to famous teachers
D.MOOCs have brought about revolution in education
小題3:What can we learn from the passage?
A.Most of the MOOCs focus on professional training for college graduates.
B.There are barriers for MOOCs to replace the present education system.
C.International companies prefer applicants who graduate from MOOCs.
D.More and more undergraduates have realized the limits of MOOCs.
小題4:The author’s attitude towards MOOCs is___________.
A.doubtfulB.negativeC.criticalD.optimistic

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

EDGEWOOD—Every morning at Dixie Heights High school, customers pour into a special experiment :the district’s first coffee shop run mostly by students with special learning needs.
Well before classes start, students and teachers order Lattes, Cappuccinos and Hot Chocolates. Then, during the first period, teachers call in orders on their room phones, and students make deliveries.
By closing time at 9.20 a.m. , the shop usually sells 90drinks.
“whoever made the chi tea, Ms. Schwartzman says it was good, ”Christy McKinley , a second year student , announced recently, after hanging up with the teacher.
The shop is called the Dixie PIT, which stands for Power in Transition. Although some of the students are not disabled, many are, and the PIT helps them prepare for life after high school.
They learn not only how to run a coffee shop but also how to deal with their affairs. They keep a timecard and receive paychecks, which they keep in check registers.
Special-education teachers Kim Chevalier and Sue Casey introduced the Dixie PIT from a similar program at Kennesaw Mountain High School in Georgia.
Not that it was easy. Chevalier’s first problem to overcome was product-related. Should schools be selling coffee? What about sugar content?
Kenton County Food Service Director Ginger Gray helped. She made sure all the drinks, which use non-fat milk, fell within nutrition(營(yíng)養(yǎng))guidelines.
The whole school has joined in to help.
Teachers agreed to give up their lounge(休息室)in the morning. Art students painted the name of the shop on the wall. Business students designed the paychecks. The basketball team helped pay for cups.
小題1:.What is the text mainly about?
A.A best-selling coffee.
B.A special educational program.
C.Government support for schools.
D.A new type of teacher-student relationship.
小題2:The Dixie PIT program was introduced in order to    .
A.raise money for school affairs
B.do some research on nutrition
C.develop students’ practical skills
D.supply teachers with drinks
小題3:How did Christy McKinley know Ms. Schwartzman’s opinion of the chi tea?
A.She met her in the shop.
B.She heard her telling others.
C.She talked to her on the phone.
D.She went to her office to deliver the tea.
小題4:We know from the text that Ginger Gray       .
A.manages the Dixie PIT program in Kenton County
B.sees that the drinks meet health standards
C.teaches at Dixie Heights High School
D.owns the school’s coffee shop

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

These days it’s cheaper to throw that broken DVD player, cell-phone or TV out and buy a new one. This “ replace-rather-than-repair” mentality is polluting the planet with electronic waste. According to the UN Environment Program, we are throwing away an estimated 50 million metric tonnes of electronics waste    (e-waste) per year. But this is not ordinary garbage. Our electronics leak harmful heavy metals — such as mercury and arsenic — along with equally poisonous chemicals that end up in our soil and eventually our water.
You’ve probably participated in a community recycling event and left feeling good about shipping off that old computer to be recycled. Chances are it was shipped overseas where it’s polluting someone else’community.
Guiyu city in Southeastern China has become known as the e-waste city where low-paid workers use whatever means available to remove electronics in hopes of recovering the copper, microchips, aluminum, gold and silver and plastic that can be resold. Any leftover waste is simply thrown into the nearby river or piled up high in the streets, poisoning the children growing up here.
So what can you do with your e-waste? Robert Houghton, President and founder of Redemtech, an asset management and recovery firm, recommends you vote with your dollar. Buy from companies who have a take-back program that guarantees your discarde electronics are handled proper.
“ Consumers want to do business with companies who are demonstrably    good with corporate responsibility and dealing with e-waste, ” said Houghton.
There are   plenty of charitable   organizations that will    take your  used electronics and donate them for charitable causes:
? Electronic Recycling  Association (Canada) (ERA) collects old    computers for donation to libraries and other organizations across Canada.
? eBay’s Rethink Initiative pairs up consumers with businesses that refurbish (再磨光)old computers for donation.
? TechSoup has a thorough   listing of resources for those who would  like   to donate or recycle hardware,buy recycled hardware or find a refurbisher.
? The Charitable    Recycling Program  accepts all cell-phones    and    has a listing of charities it helps with its program.
? Call2 Recycle has set up drop off points across Canada in a number of stores. You can drop off your cell-phone and also your rechargeable batteries from handheld electronic products.
小題1:When there is something wrong with electronics, what is a popular trend among people nowadays?
A.To keep a DIY way.B.To put them away themselves.
C.To purchase what they like.D.To donate them to charities.
小題2:Guiyu city in Southeastern China is mentioned here to show us ____.
A.there is an ideal place in the world for e-waste
B.there is a good example in the world for recycling
C.the recycling events in Canada benefit people overseas
D.people should find a scientific and thorough way to recycle
小題3:In the     writer’s opinion, who can first shoulder the   great responsibility to guarantee e-waste is handled proper in the future?
A.The UN Environment Program.
B.Consumers who buy electronics.
C.President and founder of Redemtech.
D.Guiyu city in Southeastern China.
小題4:In Canada, which charity organization will    most possibly take all  your unwanted electronics?
A.Call2 Recycle.B.TechSoup.
C.eBay’s Rethink Initiative.D.Electronic Recycling Association.

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

Redwood trees are the tallest plants on the earth,reaching heights of up to 100 meters.They are also known for their longevity,typically 500 to 1000 years,but sometimes more than 2000 years.A hundred million years ago,in the age of dinosaurs,redwoods were common in the forests of a much more moist and tropical North America.As the climate became drier and colder,they declined to a narrow strip along the Pacific coast of Northern Califomia.
The trunk of redwood trees is very strong and usually forms a single straight column.It is covered with a soft bark.This bark can be pretty thick,well over two feet in the more mature trees.It gives the older trees a certain kind of protection from insects,but the main benefit is that it keeps the center of the tree harmless from moderate forest fires because of its thickness.This fire resistant quality explains why the giant redwood grows to live that long.While most other types of trees are destroyed by forest fires,the giant redwood actually prospers because of them.
Moderate fires will clear the ground of competing plant life,and the rising heat dries and opens the ripe fruit of the redwood,releasing many thousands of seeds onto the ground below.
New trees are often produced from shoots,little baby trees,which form at the base of the trunk.These shoots grow slowly,fed by the root system of the “mother’’ tree.When the main tree dies,the shoots are then free to grow as full trees,forming a “fairy ring” of trees around the original tree.These trees,in turn,may give rise to more shoots,and the cycle continues.
小題1:Why were redwood trees easier to find in the forests of North America millions of years ago?
A.The trees were taller and stronger.
B.The soil was softer for seeds to develop.
C.The climate there was warmer and wetter.
D.The temperature was lower along the Pacific coast.
小題2:Which of the following is a function of the tree bark as mentioned in the passage?
A.It allows redwood trees to bear seeds.
B.It prevents redwood trees from attack by insects.
C.It helps redwood trees absorb water in the air.
D.It makes redwood trees more beautiful and appealing.
小題3:Why do redwood trees grow to live that long according to the passage?
A.They have heavy and straight tree trunks.
B.They are properly watered and catered to.
C.They are more resistant to fire damage than other trees.
D.They produce many young trees to maintain their life cycle.
小題4:How does a “fairy ring’’ form according to the passage?
A.By killing an old tree.B.By connecting root systems.
C.By inserting holes into old trees.D.By surrounding a mature tree.

查看答案和解析>>

同步練習(xí)冊(cè)答案