单选题在一个数列中，第一项和第二项分别是2和4，随后的每一项都是前面各项的和，如果第10项的值是n，那么第15项是多少?

单选题 ①San Lorenzo

单选题. ①Prominent among theories of the function of sleep is Meddis' immobilization hypothesis, which holds that sleep, rather than serving a restorative function, plays a protective role during times that animals cannot be usefully engaged in other activities. ②Meddis reasoned that animals not immediately threatened by predators would be safer if they passed the time sleeping. ③Sleep would prevent an animal from moving or responding to nonthreatening stimuli in ways that might attract the attention of predators. ①However, that hypothesis cannot easily explain why one often observes a rebound in sleep time or intensity following a period of sleep deprivation. ②Neither does the hypothesis explain the existence of various states of sleep, which themselves may be associated with different functions.31. According to the passage, the immobilization hypothesis fails to account for which of the following facts? ______

单选题If x, y and z are positive integers such that x is a factor of y, and x is a multiple of z, which of the following is NOT necessarily an integer?

单选题standard deviation is 4Quantity A: 出现在区间60，64 的概率Quantity B: 出现在区间64，68 的概率

单选题. ①The expectation that science is a stable body of relatively objective knowledge on which the law can draw to settle legal controversies may seem benign. ②However, this expectation often corresponds to a romantic notion of the scientific enterprise and thereby eclipses not only the instabilities and controversies within science itself, but also the social and rhetorical aspects of even the best science. ③We see the idealization of science in law whenever there is a presumption that if two scientific experts disagree, one of them must be a "junk scientist". ④This presumption ignores the theoretical presuppositions and limitations of data that lead to genuine scientific disputes. ⑤We also see the idealization of science in law whenever we associate "bias, interest, and motivation" with unreliable expertise. ⑥This association missed the practical advances made by scientists who have strong theoretical biases, institutional interests, and financial motivations. ⑦Finally, we see the idealization of science in law whenever a legislator, administrator, or judge demands certainty from science, not recognizing its probabilistic nature and dynamic history. ⑧It is neither a critique of scientific progress nor an exaggeration to acknowledge scientific debates, the conventional aspects of scientific methodology, the importance of networking and "social capital" with respect to publications and grants, and the persuasive elements in scientific discourse. ⑨To think that these features are somehow markers of bad science is to idealize science.20. The primary purpose of the passage is to ______

单选题. ①Although some skeptics points to Arctic places such as the high latitudes of Greenland, where temperatures seem to have fallen, a recent scientific report concludes that in recent decades average temperatures have increased faster in the Arctic than elsewhere. ②Scientists have long suspected that several factors lead to greater temperature swings at Earth's polar regions than elsewhere. ③First, most of the Arctic is covered in snow and ice, which are highly reflective; if snow and ice melt, the exposed soil, which absorbs heat, serves to accelerate warming. ④Second, the polar atmosphere is thin, so little energy is required to warm it. ⑤Third, less solar energy is lost in evaporation at the frigid poles than in the tropics.34. The passage mentions which of the following as factors that might lead to large temperature swings in Earth's polar regions? ______

单选题There are 120 employees in a certain company. If 36 of the employees are in the union, what percent of the employees are not in the union?

单选题从两个集合{8、9、10、11、12、13、14}和{15、16、17、18、19}中分别随机挑出一个来并且相加，问它们的和最多有几种?

单选题. ①The poet Paul Lawrence Dunbar (1872-1906) was the premier Black writer of poetry that used the dialect of rural African American of the southern United States. ②Although Dunbar's works were both popular with readers and acclaimed by literary critics during his lifetime, after the First World War a radical shift occurred, at least in critical opinion of his poetry, and twentieth-century critical evaluation of his work has been generally negative. ③Some critics attacked his work on social grounds for failing to challenge plantation stereotypes of African Americans. ④Other critics, such as the post James Weldon Johnson, argued from aesthetic grounds that dialect poetry in general was too limited as an artistic medium, and capable of producing only two effects: pathos and humor. ⑤The negative critical trend only began to reverse itself in the 1970s, when scholars began to emphasize the importance of mythic, psychological, and historical dimensions of Dunbar's works, focusing on the interior and exterior realities of African American life after the Civil War.41. Which of the following general criticisms of dialect poetry is mentioned in the passage? ______

单选题35. In the country of Seligia where asbestos has been used extensively in construction, that use is about to be banned, because the exposure of construction workers to asbestos can cause a certain type of cancer. We can predict that the ban will result in reducing the incidence of that type of cancer in Seligia by as much as 50 percent. It is true that less than 30 percent of the death certificates of Seligians who have died of that cancer have "construction" listed as the deceased's occupation. The cancer takes about 20 years after exposure to develop, however, and Seligians who have worked in construction commonly turn to less strenuous occupations as they age. Seligian death certificates indicate only the deceased's last occupation. In the argument given, the two highlighted portions play which of the following roles? ______

单选题In a certain box, there are 3 times as many red balls as blue balls. Which of the following is the ratio of the number of red balls to the number of blue balls?

单选题If the price of the clothes decreases from $25 to $20, what is the percent decrease in price?

单选题圆心在原点、半径为5的圆上有多少个整数点?

单选题 Some conservationists

单选题On a trip of 408 miles, Tom travels the first 160 miles in 4 hours. At what rate must he travel for the remainder of the trip in order to average 34 miles per hour for the entire trip? in miles per ho

单选题. ①Our study revealed that nest-guarding long-tailed skinks (a species of lizard) homed (returned to their nests) more successfully when displaced shorter distances. ②There are two reasons why homing success rates decreased with increasing displacement distance. ③One possibility is that females were simply displaced too far to find their way home. ④However, this is unlikely given that some individuals managed to find their way home from each distance we used. ⑤The second possibility deals with trade-offs between the risks associated with making a long return trip and the benefits of returning. ⑥Animals should expend energy only when the associated costs are low. ⑦As reptiles increase the time spent moving, their daily energy expenditure increases dramatically. ⑧The energetic costs of returning home and the chances that the eggs will have been preyed upon during the return trip both increase substantially as displacement distance increases. ⑨For example, the 130 hours (5.5 days) that female skinks spent returning from a distance of 300 meters is sufficient for an egg-eating snake to locate and prey upon the entire clutch. ⑩However, females with larger clutches were more likely to home at distances over 50 meters. For these females, the relative fitness benefits associated with having more eggs successfully hatch may outweigh the energetic costs of returning to a nest site, even if the nest may have already been preyed upon.25. The primary purpose of the passage is to ______

单选题 ①"Blues is for singing

单选题What is the smallest positive integer k for which 784 is a factor of 14k?

单选题Bob has 40 coins consisting only of dimes and quarters. If the number of dimes is 10 more than twice the number of quarters, what is the total value of the coins.