新SAT官方指南阅读第十三篇全解析
This passage is adapted from Thor Hanson,Feathers.©2011by Thor Hanson.Scientists have long debated how the ancestors of birds evolved the ability to fly.The ground-up theory assumes they were fleet-footed ground dwellers that captured prey by leaping and flapping their upper
limbs.The tree-down theory assumes they were tree climbers that leapt and glided among
branches.
At field sites around the world,Ken Dial saw a pattern in how young pheasants,quail, tinamous,and other ground birds ran along behind their parents.“They jumped up like popcorn,”
he said,describing how they would flap their half-formed wings and take short hops into the air.
So when a group of graduate students challenged him to come up with new data on the age-old
5斯琴高丽的伤心歌词
ground-up-tree-down debate,he designed a project to e what clues might lie in how baby game birds learned to fly.
Ken ttled on the Chukar Partridge as a model species,but he might not have made his discovery without a key piece of advice from the local rancher in Montana who was supplying
him with birds.When the cowboy stopped by to e how things were going,Ken showed him his nice,tidy laboratory tup and explained how the birds’first hops and flights would be measured. 10
The rancher was incredulous.“He took one look and said,in pretty colorful language,‘What are tho birds doing on the ground?They hate to be on the ground!Give them something to climb on!’”At first it emed unnatural—ground birds don’t like the ground?But as he thought about it
Ken realized that all the species he’d watched in the wild preferred to rest on ledges,low branches, 15
霓裳动or other elevated perches where they were safe from predators.They really only ud the ground for feeding and traveling.So he brought in some hay bales for the Chukars to perch on and then
left his son in charge of feeding and data collection while he went away on a short work trip.
Barely a teenager at the time,young Terry Dial was visibly upt when his father got back.“I asked him how it went,”Ken recalled,“and he said,‘Terrible!The birds are cheating!’”Instead of flying up to th
eir perches,the baby Chukars were using their legs.Time and again Terry had
20
watched them run right up the side of a hay bale,flapping all the while.Ken dashed out to e for himlf,and that was the“aha”moment.“The birds were using their wings and legs
cooperatively,”he told me,and that single obrvation opened up a world of possibilities.
Working together with Terry(who has since gone on to study animal locomotion),Ken came 25
up with a ries of ingenious experiments,filming the birds as they raced up textured ramps tilted at increasing angles.As the incline incread,the partridges began to flap,but they angled their
wings differently from birds in flight.They aimed their flapping down and backward,using the
force not for lift but to keep their feet firmly presd against the ramp.“It’s like the spoiler on the back of a race car,”he explained,which is a very apt analogy.In Formula One racing,spoilers are 30
the big aerodynamic fins that push the cars downward as they speed along,increasing traction and handling.The birds were doing the very same thing with their wings to help them scramble up
otherwi impossible slopes.
Ken called the technique WAIR,for wing-assisted incline running,and went on to document it in a wide range of species.It not only allowed young birds to climb vertical surfaces within the 35
first few weeks of life but also gave adults an energy-efficient alternative to flying.In the Chukar
experiments,adults regularly ud WAIR to ascend ramps steeper than90degrees,esntially
running up the wall and onto the ceiling.
In an evolutionary context,WAIR takes on surprising explanatory powers.With one fell
swoop the Dials came up with a viable origin for the flapping flight stroke of birds(something
gliding animals don’t do and thus a shortcoming of the tree-down theory)and an aerodynamic 40
function for half-formed wings(one of the main drawbacks to the ground-up hypothesis).
21、Which choice best reflects the overall quence of events in the passage?
A)An experiment is propod but proves unworkable;a less ambitious experiment is attempted, and it yields data that give ri to a new t of questions.泸沽湖旅游攻略必去景点
B)A new discovery leads to reconsideration of a theory;a classic study is adapted,and the results are summarized.党员活动日
C)An anomaly is obrved and simulated experimentally;the results are compared with previous findings,and a novel hypothesis is propod.
D)An unexpected finding aris during the early pha of a study;the study is modified in respon to this finding,and the results are interpreted and evaluated
正确答案：D
分析：文章当中，作者提到：Ken Dial设计了一个实验，这个实验旨在通过观察幼鸟Chukars 学习飞行的过程观研究飞行进化过程；在实验过程中，Ken Dial发现Chukars配合使用翅膀和爪子的独特方式，于是他又补充设计了一些实验来研究这个观察的结果。经过补充实验，Ken Dial发现了一些意料之外的结果。
党员谈心记录22、As ud in line4,“challenged”most nearly means
手机qq病毒A)dared.
B)required.
C)disputed with.
D)competed with.
大学文言文
正确答案：A
分析：文章当中提到，一群研究生向Ken Dial提出挑战，要开发一批关于Ground up和Tree down理论的新数据。Challenge和dare都表示挑战。
23、Which statement best captures Ken Dial’s central assumption in tting up his rearch?
A)The acquisition of flight in young birds sheds light on the acquisition of flight in their evolutionary ancestors.
B)The tendency of certain young birds to jump erratically is a somewhat recent evolved behavior.
C)Young birds in a controlled rearch tting are less likely than birds in the wild to require perches
when at rest.
新疆是个好地方
D)Ground-dwelling and tree-climbing predecessors to birds evolved in parallel.
正确答案：A
分析：Ken Dial原本设计的实验是搜集古老鸟类关于飞行进化的数据（new data on the age-old ground-up-tree-down debate），结果他从幼鸟学习飞行的过程中去寻找线索（look for clues in how baby game birds learned to fly.）这样的策略表明：Ken Dial假设幼鸟飞行行为可以解释古老鸟类的飞行进化史。Shed light on的意识是：阐明，使……清晰地显出。
24、Which choice provides the best evidence for the answer to the previous question?
A)Lines1-2(“parents”)
B)Lines3-6(“fly”)
C)Lines9-10(“asured”)
D)Line13(“he ground”)
正确答案：B
分析：见第23题解释。
25、In the cond paragraph(lines7-17),the incident involving the local rancher mainly rves to
A)reveal Ken Dial’s motivation for undertaking his project.
B)underscore certain differences between laboratory and field rearch.
C)show how an unanticipated piece of information influenced Ken Dial’s rearch.
D)introduce a key contributor to the tree-down theory.
正确答案：C
分析：当一名农民观察Ken Dial的实验时，对于Chukars生活在地面这一点有怀疑，于是建议Dial要提供一些道具给幼鸟爬行。这一条重要建议使得Dial在他的试验中增添了一些干草。
26、After Ken Dial had his“‘aha’moment”(line22),he
A)tried to train the birds to fly to their perches.
B)studied videos to determine why the birds no longer hopped.
C)obrved how the birds dealt with gradually steeper inclines.
D)consulted with other rearchers who had studied Chukar Partridges.
正确答案：C
分析：在Ken Dial的“喜悦时刻”之后，他录制了这些鸟类爬上更加陡峭斜坡的画面（He
