第一篇
Why Buy Shade-Grown Coffee?
When people argue about whether coffee is good for health,they're usually thinking of the health of the coffee drinker.Is it food for your heart? Does it increase blood pressure? Does it help you concentrate? However,coffee affects the health of the human population in other ways,too.
Traditionally,coffee bushes were planted under the canopy（树冠)of taller indigenous（土生土长的)trees.However,more and more farmers in Latin America are deforesting the land to grow full-sun coffees.At first,this increases production because more coffee bushes can be planted if there aren't any trees.With increased production come increased profits.
Unfortunately,deforesting for coffee production immediately decreases local-wildlife habitat.Native birds nest and hide from predators（捕食者)in the tall trees and migrating birds rest there.
Furthermore,in the long term,the full-sun method also damages the ecosystem because more chemical fertilizers and pesticides are needed to grow the coffee.The fertilizers and pesticides kill insects that eat coffee plant,but then the birds eat the poisoned insects and also die.The chemicals kill or sicken other animals as well,and can even enter the water that people will eventually drink.
Fortunately,farmers in Central and South America are beginning to grow more coffee bushes in the shade.We can support these farmers by buying coffee with such labels as "shade grown" and "bird friendly." Sure,these varieties might cost a little more.But we're paying for the health of the birds,the land,ourselves,and the planet.I think it's worth it.he fertilizers and pesticides kill insects that eat coffee plant,but then the birds eat the poisoned insects and also die.The chemicals kill or sicken other animals as well,and can even enter the water that people will eventually drink.Fortunately,farmers in Central and South America are beginning to grow more coffee bushes in the shade.We can support these farmers by buying coffee with such labels as "shade grown" and "bird friendly." Sure,these varieties might cost a little more.But we're paying for the health of the birds,the land,ourselves,and the planet.I think it's worth it.
31.What is the main idea of this passage?
A.Farmers are changing the way they grow coffee.
B.Coffee is becoming more expensive to produce.
C.Shade-grow coffee is more expensive than sun-grow coffee.
D.People should buy shade-grown coffee.
32.The function of the word "Traditionally" in Paragraph 2 is to show_____.
A.the positive effects of coffee.
B.a change of coffee growth.
C.something that is the most important.
D.how coffee production used to be.
33.What does increased production of full-sun coffee bring about?
A.More insects.
B.Better quality coffee.
C.Larger farms.
D.Higher profits.
34.How do farmers find more land for growing full-sun coffee?
A.They buy more land from other farmers.
B.They cut down trees.
C.They move to another country.
D.They turn grassland into farmland.
35.The full-sun method may affect the following EXCEPT_____.
A.insects
B.air
C.brids
D.humans
第二篇
Soot（煤烟灰)and Snow： a Hot Combination
New reasearch from NASA scientists suggests emissions of black soot after the way sunlight reflects off snow.According to a computer simulation,black soot may be responsible for 25 percent of observed global warming over the past century.
Soot in the higher latitudes（维度)of the Earth,where ice is more common,absorbs more of the sun's energy and warmth than an icy,white background.Dark-colored black carbon,or soot,absorbs sunlight,while lighter colored ice reflects sunlight.
Soot in areas with snow and ice may play an important role in climate change.Also,if snow and ice covered areas begin melting,the warming effect increase,as the soot becomes more concentrated on the snow surface."This provides a positive feedback,as glaciers and ice sheets melt,they tend to get even dirtier." said Dr.James Hansen,a researcher at NASA's Goddard Institute for Space Studies,New York.
Hansen found soot's effect on snow albedo（反照率),which may be contributing to trends toward early springs in the Northern Hemisphere,such as thinninbg Arctic sea ice and melting glaciers permafrost.Soot also is believed to play a role in changes in the atmosphere above the oceans and land.
"Black carbon reduces the amount of energy reflected by snow back into space,thus heading the snow surface more than if there were no black carbon," Hansen said.Soot's increased absorption of solar energy is especially effecntive in warming the world's climate." This forcing is unusually effective,causing twice as much global warming as a carbon-dioxide forcing of the same magnitude." Hansen noted.
Hansen cautioned,although the role of soot in altering global climate is substantial,it does not alter the fact that greenhouse gases are the primary cause of climate warming during the past century.Such gases are expected to bi the largest climate forcing for the rest of the century.
The researchers found that observed warming in the Northern Hermisphere was large in the winter and spring at middle and high latitudes.These observations were coherent with the researchers' climate model situations,which showed some of the largest warming effects occurred when there were heavy snow cover and sufficient sunlight.
36.Which of the following statements of soot is NOT true?
A.It absorbs sun's heat.
B.It is responsible for climate change.
C.It reflects sunlight.
D.It may account for a quarter of global warming over the past century.
37.Which of the following areas shows a greater warming effect?
A.Ice sea areas.
B.Areas with black carbon.
C.Areas covered with white snow.
D.Melting glaciers.
38."This forcing" in Paragraph 5 refers to?
A.sun's heating on snow surface.
B.soot's increased absorption of solar energy.
C.carbon-dioxide's warming effect.
D.snow's increased reflection of sunlight.
39.What is the main cause of climate warming during the past century?
A.Soot.
B.Snow.
C.Greenhouse gases.
D.Wind.
40.The largest warming effects happened in the Northern Hemisphere with
A.X sea ice and insufficient sunlight.
B.light snow cover and sufficient sunlight.
C.heavy snow cover and sufficient sunlight.
D.thick sea ice and insufficient sunlight.
