51. The passage focuses on　　　 .

A. programs of collecting taxes　　　　　 B. systems of reducing carbon emissions

C. reasons for reducing carbon emissions　 D. contradictions between the two systems

50、We can infer from the passage that David Johnson　　　 .

A. owns several wineries in Canada

B. buys lambs from New Zealand

C. is concerned about protecting the environment

D. loves keeping lambs instead of farming

B

Everyone agrees that it’s necessary to reduce carbon emissions(排放物)around the world. There is less agreement over exactly how nations should go about achieving a more carbon free planet. Thus, the environmental equivalent: cap-and-trade carbon　 emissions, or place a carbon tax on all users?

With cap-and-trade programs, governments limit the level of carbon produced by an industry, Companies that hold their emissions below the cap can sell their remaining allowance on a carbon market, while companies that go beyond their limit must purchase credits on that market. Carbon taxes are more straightforward：as set tax rate is placed on the consumption of carbon with the idea that raising the price will encourage industries and individuals to consume less. At the moment, cap-and=trade has the upper hand, but doesn^’t defeat the tax just yet.

Supporters of the tax argue that a cap-and-trade system would be too difficult to administer-and too easily gamed by industries looking to sidestep emissions caps. Cap-and-trade advocates contradict that like all other flat taxes, a carbon collection would relatively burden lower-income families, who spend a greater percentage of their income on energy than rich households.

So which system will have a larger effect on carbon consumption? A 10% carbon tax might reduce the demand for carbon about 5% or less, according to an analysis by the Carbon Tax Center, an environmental advocacy group. That may not be enough. Businesses and governments haven’t figured out how the two competing systems can work together, but in the end, the world may need both.

49、Paragraph 4 is manly about　　　 .

A. the future of getting lambs to do the cutting

B. the worries about using organic pesticides

C. the ways to get lambs to do the cutting

D. the problems related to lambs doing the cutting

48、Which of the following statements about using lambs to do the cutting is WRONG?

A. Using lambs costs more than hiring workers.

B. Lambs won’t eat the grapes.

C. David Johnson learned this way in New Zealand

D. Lambs can be eaten after the cutting is done.

47、In order to help the grapes grow better, growers　　　　 .

A. only have to remove the dead leaves

B. need to remove a specific area of leaves

C. shouldn’t remove any part of the plants

D. should let little lambs do the cutting

46、Farmers who grow grapes with natural and organic methods　　　 .

A. don’t cut grapevines every year

B. don’t use chemicals to control harmful insects and weeds

C. don’t need to control harmful insects and weeds

D. don’t use organic fertilizer

44、A. ordering　　 B. warning　　　 C. telling　　　 D. reminding

43、A. seldom　　　 B. hardly　　　 C. never　　　　 D. always

42、A. sad　　　　 B. angry　　　　 C. tired　　　　 D. glad