单选题 ①In the 1980s

单选题. ①The ability to recognize specific individuals has profound implications for the evolution of complex social behaviors such as reciprocal altruism. ②Many researchers assumed that recognition of individuals, a phenomenon predominantly observed in laboratory studies of fish, might also operate extensively in free-ranging fish populations, where it could underpin complex interactions. ③In fact, evidence of individual recognition in free-ranging fish populations is equivocal. ④The possibility exists that for many species, individual recognition observed in the laboratory might be an artifact of experimental designs, which enforce prolonged interaction between individuals and which prevent the diluting effects on social structure of immigration into and emigration from the shoal, factors that in nature would erode group stability and prevent the learning of individual identities.17. The passage is primarily concerned with ______

单选题 ① Pueblo Bonito

单选题三角形的两条边分别是4和6Quantity A: 三角形的面积SQuantity B: 13

单选题Rolling a number cube with faces numbered 1 to 6 similar to a 6-sided die is an experiment with 6 possible outcomes: 1, 2, 3, 4, 5 or 6. If we toss two number cubes simultaneously, what is the possibl

单选题7. Princessfish are a species of coral-reef fish that are captured alive by divers who first stun the individual fish by squirting a certain poison at them. Since the divers limit their catch to a few individuals and take care not to overfish, the divers' continuing activities will clearly not result in serious harm to populations of princessfish. Which of the following, if true, most seriously weaken the argument given? ______

单选题 ①Carla L. Peterson's Doers of the Word (1997)

单选题Quantity A: the root of x2+2x+1=0Quantity B: the root of x2-4x+3=0

单选题 ①Archaeologists studying Bonito phase (ca. A.D

单选题Two keys are to be put into the key chain that already has 5 keys. What is the probability that these two keys will be next to each other?

单选题Which of the following is the coefficient of xy in3x+4y-xy4x+3y+1?

单选题11. Samples taken from the ice of glaciers show that during the last ice age there was far more dust in the atmosphere than there is now. Since greater amounts of dust in the atmosphere would result in less sunlight's reaching the Earth's surface, it is likely that the large amount of dust then present helped maintain low global temperatures and thus prolonged the ice age. Which of the following, if true, most seriously weaken the argument? ______

单选题 ①The United States Civil Rights movement

单选题One hour after Tom started walking from X to Y, a distance of 45 miles. Bob started walking along the same road from Y to X. If Tom’s walking rate was 3 miles per hour and Bob’s was 4 miles per hour,

单选题. ①Throughout much of the Tertiary period(most of the past 65 million years), the Arctic supported continuous forests. ②Only toward the end of that period does the fossil evidence show that certain present-day Arctic plants were established and widely distributed throughout the Arctic. ③Many Arctic plants are thought to have originated in the high mountain ranges of central Asia and North America, to have spread northward to the Arctic as global temperatures fell in the late Tertiary, and to have achieved a circumpolar distribution by the end of the Tertiary(about 2 million years ago). ④However, fossil evidence to support these proposals is either lacking or fragmentary. ⑤Consequently, the routes by which these plants expanded their ranges during their colonization of the Arctic remain unknown.15. Which of the following statements about Arctic plants is supported by the passage? ______

单选题. ①Benjamin Franklin is portrayed in American history as the quintessential self-made man. ②In "Self-reliance," Emerson asks, "Where is the master who could have instructed Franklin...?" ③In fact, Franklin took instruction widely, and his scientific work was highly collaborative. ④Friends in England sent equipment needed for his electrical experiments, others, in Philadelphia, helped him set up his workshop there. ⑤Philip Syng constructed a device for generating electrical charges, while Tomas Hopkinson demonstrated the potential of pointed conductors. ⑥Franklin, in addition to being the group's theoretician, wrote and published its results. ⑦His fame as an individual researcher is partly a consequence of the shorthand by which when one person writes about a group's discoveries, history sometimes grants singular credit for collective effort.45. Which of the following best describes the function of the highlighted sentence? ______

单选题3. The use of nets at beach resorts to protect swimming areas from sharks has been criticized by environmentalists because the nets needlessly kill thousands of marine animals annually. However, environmentalists have recently discovered that an electrified cable buried beneath the periphery of swimming areas causes sharks to swim away while harming neither humans nor marine life. Hence, by installing such cables, resort communities will be able to maintain tourism while satisfying environmentalists' concerns. Which of the following, if true, most seriously weakens the argument? ______

单选题. ①David Belasco's 1912 Broadway production of The Governor's Lady created a sensation with a scene set in a Child's cafeteria, a chain restaurant that was an innovator in food standardization and emblematic of modern everyday life. ②While Belasco's meticulously detailed reproduction of an immediately recognizable setting impressed the public, it was derided by progressive theater critics who championed the New Stagecraft theories of European artists like Max Reinhardt. ③The New Stagecraft rejected theatrical literalism; it drew inspiration from the subjectivity and minimalism of modern painters, advocating simplified sets designed to express a dramatic text's central ideas. ④Such critics considered Belasco a craftsman who merely captured surface realities: a true artist eliminated the inessential to create more meaningful, expressive stage images.47. The author of the passage implies which of the following about Belasco's production of The Governor's Lady? ______

单选题Both m and n are positive integers greater than 1.If 23m-2=21n-3，what is the least possible value of m+n?