共用题干Vision
Human vision like that of other primates（灵长目）has evolved in an arboreal（丛林）environment.______(46)
In the course of evolution,members of the primate line have acquired large eyes while the nose has shrunk.______ (47) Of mammals（哺乳动物）only humans and some primates enjoy color vision.______(48)Horses live in a single-color world.
Light visible to human eyes,however,occupies only a very narrow band in the whole electromagnetic spectrum（光谱）.Ultraviolet rays（紫外线）are invisible to humans though ants and honeybees are sensitive to them.______(49)The world would look terribly different if human eyes were、 sensitive to infrared radiation（红外线）.Then instead of the darkness of night,we would be able to move easily in a strange shadowless world.______(50)
But human eyes excel in other ways. They are in fact remarkably discerning in color gradation. The color sensitivity of normal human vision is rarely surpassed even by complicated technical devices. _________（50）A:Humans have no direct perception of infrared rays.B:In the dense complex world of a tropical forest,it is more important to see well than to develop an acute sense of smell.C:That gives the eye a wilder view.D:The red flag is black to the bull.E:There are different mammals in tropical forest.F: In this world,objects glowed with varying degrees of intensity.

In Sports, Red Is the Winning Color When opponents of a game are equally matched, the team dressed in red is more likely to win, according to a new study. British anthropologists Russell Hill and Robert Barton of the University of Durham reached that conclusion by studying the outcomes of boxing, tae kwon do, Greco-Roman wrestling (摔跤),and freestyle wrestling matches at the 2004 Summer Olympics in Athens, Greece. In each event, Olympic staff randomly assigned red or blue clothing or body protection to competitors. When competitors were equally matched with their opponent in fitness and skill, the athletes wearing red were more likely to win. "Where there was a large point difference — presumably because one athlete was far superior to the other — color had no effect on the outcome," Barton said. "Where there was a small point difference, the effect of color was sufficient to tip the balance.” Joanna Setchell, a primate (灵长目)researcher at the University of Cambridge in England, has found similar results in nature. Her work with the large African monkeys known as mandrills shows that red coloration gives males an advantage when it comes to mating. The finding that red also has an advantage in human sporting events does not surprise her, and she adds that "the idea of the study is very clever." Hill and Barton got the idea for their study from a mutual interest in primates — "red seems to be the color, across species, that signals male dominance," Barton said. For example, studies by Setchell, the Cambridge primate researcher, show that dominant male mandrills have increased red coloration in their faces and rumps (臀部). In another study, scientists put red plastic rings on the legs of male zebra finches (斑胸草雀), which increased the birds’ success in finding a mate. Barton said he and Hill speculated that "there might be a similar effect in humans.” Hill and Barton found their answer by viewing Olympic competitors in the ring, on the mat, and in the field. "Across a range of sports, we find that wearing red is consistently associated with a higher probability of winning, the researchers write. Barton adds that this discovery of red’s advantage might lead to new regulations on sports uniforms. In the Olympic matches he studied, for example, it is possible that some medal winners may have had an unintended advantage — their clothing! Both Hill and Barton wanted to find out if color affects the outcomes of sports matches.
A. RightB. WrongC. Not mentioned