2021年12月4日雅思考试机经回忆完整版(6)

2021年12月4日雅思考试机经回忆完整版(6) 关于这个问题下面小编就来为各个考生解答下。

2021年12月4日雅思考试机经回忆完整版(6) 

READING

Passage 3

Topic：Honey Bees in Trouble

I Honey Bees in Trouble

Can native pollinators fill the gap?

Recently, ominous headlines have described a mysterious ailment, colony collapse disorder (CCD), which is wiping out the honeybees that pllinate many crops. Without honeybees,

the story goes, fields will be sterile, economies wil collapse, and food will be scarce. But what few accounts acknowledge is that whafs at risk is not itself a natural state of affairs.

For one thing, in the United States, where CCD was first reported and has had its greatest impacts, honhoneybees are not a native species. Pollination in modem agriculture isn't

alchemy, ifs industry. The total number of hives involved in the u.S. pllination industry has been somewhere between 2.5 milion and 3 million in recent years. Meanwhile, American

farmers began using large quantitles of organophosphate insecticides, planted large-scale crop monocultures, and adopted "clean farming., practices that scrubbed native vegetation

from field margins and roadsides. These practices klled many native bees outright they're a vulnerable to insecticides as any agricultural pest 一and made the agricultural landscape inhospitable to those that remained. Concern about these practices and their effects on pllinators isn't new, in her 1962 ecological alarm cry Silent Spring，Rachel Carson warned of a Truitless Fall* that could result from the ( disappearance of insect pollinators.

If that 'Fruitless Fair has not一yet 一occurred, it may be largely thanks to the honeybee, which farmers turned to as the ability of wild pllinators to service crops declined. The

honeybee has been semi-domesticated since the time of the ancient Egyptians, but it wasn't just familiaity that determined this choice: the bees' biology is in many ways suited to the

kind of agricultural system that was emerging. For example, honeybee hives can be closed up and moved out of the way when pesticides are aplied to a field. The bees are generalist

pollinators, so they can be used to pllinate many dfferent crops. And although they are not the most eficient pollinator of every crop, honeybees have strength in numbers, with 20,000

to 100.000 bees living in a single hive. <4Without a doubt, if there was one bee you wanted for agriculture, it would be the honeybee,M says Jim Cane, of the U.S. Department of

Agriculture, The honeybee, in other words, has become a crucial cog in the modem system of industrial agriculture. That system delivers more food, and more kinds of it, to more

places, more cheaply than ever before. But that system is also vulnerable, because making a farm field into the photosynthetic equivalent of a factory floor, and pollination into a series

of continent-long assembly lines, also leaches out some of the resilience characteristic natural ecosystems.

Breno Freitisa, a agronomist in Brail, pointed out that in nature such a high degree of spelalsation usually is a very dangerous game: it works well while all the rest Is in eulbrium, but runs quickly to extintion at the least disbalance. In efect, by developing an agicultural system that is heavily rliant on a single pllinator species, we humans have become riskily overspecialized. And when the human-honeybee relationship is disrupted, as it has been by colony ollapses disorder, the vulnerability of that griulural system begins to become clear.

In fact, a few wild bees are aleady being sucesstully managed for crop pllination. "The problem Is trying to provide native bees in adequate numbers on a ellable basls in a fairty

short number of years In order to service the crop," Jim Cane says, "You're talklng mllons of flowers per acre in a two-to three-week time frame, or less, for a lot of crops." On the other

hand, native bees can be much more eficient pllinators of certain crops than honeybees.

s0 you don't need as many to do the job. For example, about 750 blue orchard bees (Osmia lignaria) can pllinate a heetare of apples or almonds,确task that would require roughIy 50.000 to 150,000 honeybees. There are bee tinker- ers engaged in similar work in many comers of the wordl, In Brazil, Breno Freitas has found that Centis tarsata, the native pollinator of wild cashew, can survive in commercial cashew orchards if growers provide a source of floral lls, such as by inter planting their cashew tes with Caribbean cherry.

In certain placee, native beee may already be doing more than they're geting credit for. Ecolgist Rachae! Winfree recenty led a team that looked at pllination of four summer crops

(tomato, watermelon. peppers, and muskmelon) at 29 farms in the region of New Jersey and Pennsylvania. Winfree's team identifed 54 species of wild bees that visted these crops, and

found that wild bees were the most Importans Pllinators in the system: even though managed honeybees were present on many of the farms, wild bees were responsible tor 62 percent of flower visits in the study. In another studty focusing speifcally on watermelon,Winfree and her clleagues cakculated that native bees alone could provide sfficient pollination at 90 percent of the 23 farms studied. By contrast, honeybees alone could provide sufcient pllination at only 78 percent of farms.

"The region I work in is not typical of the way most food is produced.M Winfree admits. In the Delaware Valley. most farms and farm fielde are rlatively emall, each farmer tpically grows

a variety of crops, and farms are interspersed with suburbs and other types of land use which means there are opportunities for homeowners to get involved in bee conservation,

too. The landscape is a bee-triendly patchwork that provides a variety of nesting habitat and floral resources distributed among dfferent kinds of crops, weedy feld margins, tal low fiekds,suburban neighborhoods, and semi natural habitat like old woodlots, all at a relalively small scale. In other words, 4-pollinator- friendly,, faming practices would not only aid pollination of agrcutural crops, but also serve as a key element in the ower all eonservatlon strategy ftr wild pllinators, and often aid other wild species as well, Of course, not all farmers will be able to implement all of these practices. And researchers are suggesting a shit to a kind of polyglot agricultural system. For some small-scale farms, native bees may indeed be all thal's needed. For larger operations, a suite of managed bees with honeybees fling the generalst role and other, native bees pllinating specilie crops could be augmented by free pllination services from resurgent wild pllinator. In other words, theySre saying, we stll have an opportunity to replace a risky monoculture with something diverse, resilienii and robust.

题目方面

27-30为判断题

27. In the United States, farmers use honeybees in a large scale over the past few years.YES

28. Clean fanning pracices would be harmful to farmers9 health.NOT GIVEN

29. The blue orchard bee 8 the most eicient pllinator for every crop. NO

30. It is benefcial to cther local creatures to protect native bees,YES

31-35为选择题

31. The example of the "Fruitless Fall5 underlines the writer's polnt about

A needs for using pesticides.

B impacts of losing insect pollinators.

C vulnrabilities of native bees.

D benefite in building more pllination industries.

32 Why can honeybees adapt to the modem agriculural system?

A The honeybes can pllinated more crops efriently.

B The bees are seml-domesticated since ancient times.

C Honeybee hlves can be protected from pestlcldes.

D The ability of wild pllinators using to serve crops declines.

33 The writer mentions factories and assembly lines to ilustrate

A one drawback of the industrialized agricultural system.

B a low cost in modem aricullure.

C the role of honeybees in pllination.

D what a high yield of industrial agriculture.

34 In the 6th paragraph, Winfree experiment proves that

A honeybees can pllinate various crops.

B there are many types of wild bees as the pllinators.

c wild bees can increase the yield to a higher percentage.

D wild bees work more flicinlly a站a pllinalor than honeybees in certain

35 What does the writer want to suggest in the last paragraph?

A the importance of honeybees in pllination

B the adoption of different bees in various sizes of agricultural system

C the comparison between the intensive and the rarefied agricultural system

D the reason why farmers can rely on native pollinators

36-40为匹配题

36. Headlines of colony collapse disorder state that B

37. Viewpoints of Freitas manifest that F

38. Examples of blue orchard bees have shown that E

39. Centris tarsata is mentioned to exemplify that A

40. One finding of the research in Delaware Valley is that D

A. native pollinators can survive when a specific plant is supplied.

B. it would cause severe consequences to both commerce and agriculture.

C. honeybees can not be bred.

D. some agricultural landscapes are favourable in supporting wild bees.

E. a large scale of honeybees are needed to pollinate.

F. an agricultural system is fragile when relying on a single pollinator,

由于篇幅的问题，以上只是一部分，更多内容请继续关注我们中国教育在线外语频道。

>> 雅思 托福 免费测试、量身规划、让英语学习不再困难<<