2016-12-31 15:00:56 | 来源:网络及考生回忆
材料
Most of us walk and carry items in our hands every day. These are seemingly simple activities that the majority of us don't question. But an international team of researchers, including Dr. Richmond from GW' s Columbian College of Arts and Sciences, have discovered that human walking upright,may have originated millions of years ago as an adaptation to carrying scarce,high-quality resources. The team of researchers from the U. S., England, Japan and Portugal investigated the behavior of modern-day chimpanzees as they competed for food resources, in an effort to understand what ecological settings would lead a large ape-one that resembles the 6 million year old ancestor we shared in common with living chimpanzees-to walk on two legs.“These chimpanzees provide a model of the ecological conditions under which our earliest ancestors might have begun walking on two legs,”,said Dr. Richmond.
The research findings suggest that chimpanzees switch to moving on two limbs instead of four in situations where they need to monopolize a resource. Standing on two legs allows them to carry much more at one time because it frees up their hands. Over time, intense bursts of bipedal activity may have led to anatomical changes that in turn became the subject of natural selection where competition for food or other resources was strong.
Two studies were conducted by the team in Guinea. The first study was conducted by the team in Kyoto University’s “outdoor laboratory ” in a natural clearing in Bossou Forest. Researchers allowed the wild chimpanzees access to different combinations of two different types of nut-the oil palm nut, which is naturally widely available, and the coula nut, which is not. The chimpanzees’behavior was monitored in three situations:(a) when only oil palm nuts were available, (b)when a small number of coula nuts were available, and(c) when coula nuts were the majority available resource.
When the rare coula nuts were available only in smal1 numbers, the chimpanzees transported more at one time. Similarly, when coula nuts were the majority resource, the chimpanzees ignored the oil palm nuts altogether. The chimpanzees regarded the coula nuts as a more highly-prized resource and competed for them more intensely.
In such high-competition settings, the frequency of cases in which the chimpanzees started moving on two legs increased by a factor of four. Not only was it obvious that bipedal movement allowed them to carry more of this precious resource, but also that they were actively trying to move as much as they could in one go by using everything available —even their mouths.
The second study,by Kimberley Hockings of 0xford Brookes University, was a 14-month study of Bossou chimpanzees crop-raiding, a situation in which they have to compete for rare and unpredictable Resources. Here, 35 percent of the chimpanzees activity involved some sort of bipedal movement, and once again, this behavior appeared to be linked to a clear attempt to carry as much as possible at one time.
114、Which of the following statements is NOT true according to the first two paragraphs?( )
A、Many people question the simple human activities of walking and carrying items.
B、Chimpanzee’ s behaviors may suggest why humans walk on two legs.
C、Human walking upright is viewed as an adaptation to carrying precious resources.
D、Our ancestors' ecological conditions resembled those of modern-day chimpanzees.
115、Dr. Richmond conducted the experiment with the purpose of finding?( )
A、when humans began walking on two legs.
B、what made our ancestors walk upright.
C、what benefits walking upright brought to our ancestors.
D、how walking upright helped chimpanzees monopolize resources.
116、Kyoto, University' s study discovered that chimpanzees?( )
A、regarded both types of nut as priced resources.
B、preferred oil palm nuts to coula nuts.
C、liked coula nuts better than oil palm nuts.
D、ignored both types of nut altogether.
117、Why did the chimpanzees walk on two limbs during Kyoto University' s experiment?( )
A、Because they imitated the human way of walking just for fun.
B、Because they wanted to please the researchers to get more coula nuts from them.
C、Because they wanted to get to die nut-rich forest faster by walking that way.
D、Because they wanted to carry more nuts with two free limbs.
118、What can we infer from the reading passage?( )
A、Chimpanzees are in the same process of evolution as our ancestors were.
B、Chimpanzees are similar to humans in many behaviors.
C、Walking on two limbs and walking on four limbs each have their advantages.
D、Human walking on two legs developed as a means of survival.
材料
NASA scientists said that Mars was covered once by vast lakes, flowing rivers and a variety of other wet environments that had the potential to support life.
Laboratory tests aboard NASA' s Phoenix Mars Lander2 have identified water in a soil sample; the lander' s robotic arm delivered the sample Wednesday to an instrument that identifies vapors produced by the heating of samples. .
“We have water,” said William Boynton of the University of Arizona, lead scientist for the Thermal and Evolved-Gas Analyzer3,or TEGA. “This is the first time Martian water has been touched and tasted.”
The robotic arm is a critical part of the. Phoenix Mars mission. It is needed to trench into the icy layers of northern polar Mars and deliver samples to instruments that will analyze what Mars is made of,what its water is like,and whether it is or has ever been a possible habitat for life.
The soil sample came from a trench approximately 2 inches deep. When the robotic arm first reached that depth, it hit a hard layer of frozen soil. Two attempts to deliver samples of icy soil on days when fresh material was exposed were foiled when the samples became stuck inside the scoop. Most of the material in Wednesday' s sample had been exposed to the air for two days,letting some of the water in the sample vaporize away and making the soil easier to handle.
“Mars is giving us some surprises,” said Phoenix principal investigator Peter Smith of the University of Arizona. “We're excited because surprises are where discoveries come from. One surprise is how the soil is behaving. The ice-rich layers stick to the scoop when poised in the sun above the deck,different from what we expected, from all the Mars simulation testing we've done so far.”
Since landing on May 25, Phoenix has been studying soil with a chemistry lab, TEGA, a microscope,a conductivity probe and cameras. The science team is trying to determine whether the water ice ever thaws enough to be available for biology and if carbon-containing chemicals and other raw materials for life are present.
The mission is examining the sky as well as the ground. A Canadian instrument is using a laser beam to study dust and clouds overhead.
“It's a 30-watt light bulb giving us a laser show on Mars,” said Victoria Hipkin of the Canadian Space Agency.
A full-circle, color panorama of Phoenix's surroundings also has been completed by the spacecraft.“The details and patterns we see in the ground show an ice-dominated terrain as far as the eye can see,” said Mark Lemmon of Texas A&M University,lead scientist for Phoenix's Surface Stereo Imager4 camera. They help us plan measurements we're making within reach of the robotic arm and interpret those measurements on a wider scale.”
119、What was discovered by NASA's Phoenix Mars Lander on Mars?( )
A、Vast lakes.
B、Flowing rivers.
C、Water in a soil sample.
D、Living things.
120、Why did the first two attempts to deliver samples fail?( )
A、The sample vaporized away.
B、Fresh material was exposed to the air.
C、The samples got stuck inside the scoop.
D、The robotic arm hit a hard rock.
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