单选题4. In the 1600s there was intense competition in Europe to discover how to make porcelain. The two groups of Europeans working in China—Dutch merchants and French missionaries—each tried to discover the Chinese manufacturers' secrets. The first French missionary journal, was not published until 1717, several years after European porcelain manufacture began. Therefore, rather than copying the Chinese techniques, the European manufacturers must have learned by experiment. Which of the following, if true, provides the strongest support for the argument? ______

单选题If x ≥ 9 and y≤5, then it must be true that

单选题. ①Astronomers who study planet formation once believed that comets—because they remain mostly in the distant Oort cloud, where temperatures are close to absolute zero—must be pristine relics of the material that formed the outer planets. ②The conceptual shift away from seeing comets as pristine relics began in the 1970s, when laboratory simulations revealed there was sufficient ultraviolet radiation reaching comets to darken their surfaces and there were sufficient cosmic rays to alter chemical bonds or even molecular structure near the surface. ③Nevertheless, astronomers still believed that when a comet approached the Sun—where they could study it—the Sun's intense heat would remove the corrupted surface layer, exposing the interior. ④About the same time, though, scientists realized comets might contain decaying radioactive isotopes that could have warmed cometary interiors to temperatures that caused the interiors to evolve.4. According to the passage, astronomers recognize which of the following as being liable to cause changes to comets? ______

单选题从前100个正整数中选出两个数a和bQuantity A: the probability that both a and b are even integersQuantity B: the probability that a+b is even integer

单选题 ①What causes size variation in bumblebee workers

单选题Which of the following inequalities is equivalent to -3＜x＜5?

单选题. ①By far the most popular United States literature of its time was a body of now-neglected novels written between 1820 and 1870 by, for, and about women. ②According to Nina Baym, who has termed this genre "woman's fiction," the massive popularity of these novels claimed a place for women in the writing profession. ③The novels chronicle the experiences of women who, beset with hardships, find within themselves qualities of intelligence, will, resourcefulness, and courage sufficient to overcome their obstacles. ④According to Baym, the genre began with Catharine Sedgwick's New-England Tale (1822), manifested itself as the best-selling reading matter of the American public in the unprecedented sales of Susan Warner's Wide, Wide World (1850), and remained a dominant fictional type until after 1870. ⑤The critical, as opposed to popular, reception of these novels in their own time was mixed. ⑥Theoretical opposition by those who saw fiction as a demoralizing and corrupting influence was by no means dead in mid-nineteenth-century America, and popular successes naturally bore a significant proportion of the attack. ⑦The moralistic tone of much woman's fiction did not placate these antagonists; on the contrary, many clerical opponents of the novel thought that women were trying to take over the clergy's functions and hence attacked all the more fiercely. ⑧Similarly, some male authors, disgruntled by the emergence of great numbers of women writers, expressed contempt for the genre. ①On the other hand, the women had a powerful ally—their publishers, who not only put these works into print but advertised them widely and enthusiastically. ②Some few reviewers wrote about these works with attention and respect, distinguishing between the works of the different authors and identifying individual strengths and weaknesses. ③These approving contemporary critics were particularly alert to each writer's contribution to the depiction of American social life, especially to regional differences in manners and character types. ④On the whole, however, even these laudatory critics showed themselves uninterested in the stories that this fiction told, or in their significance. ①Baym acknowledges that these novels are telling—with variations—a single familiar tale, and correctly notes that this apparent lack of artistic innovation has been partly responsible for their authors' exclusion from the canon of classic American writers traditionally studied in university literature courses. ②Baym points out, however, that unlike such male contemporaries as Nathaniel Hawthorne, these women did not conceive of themselves as "artists," but rather as professional writers with work to do and a living to be made from fulfilling an obligation to their audience. ③This obligation included both entertainment and instruction, which are not, says Baym, at odds with one another in these books, nor is entertainment the sweet coating on a didactic pill. ④Rather, the lesson itself is an entertainment: the central character's triumph over adversity is profoundly pleasurable to those readers who identify with her.41. The passage is primarily concerned with ______

单选题 ①For centuries

单选题The number n is between 2 and 8, inclusive, on the number line means which of the following?

单选题有一棵树，高为10米，现在在其五等分fifths和三等分thirds处被做标记，如果这棵树要在标记处被截断，下面哪一个给出了所有不同的被截后树的长度?

单选题How many integers between 1 and 2,000 will be the square of an integer and also be the cube of an integer?

单选题. ①Recent studies of ancient Maya water management have found that the urban architecture of some cities was used to divert rainfall runoff into gravity-fed systems of interconnected reservoirs. ②In the central and southern May Lowlands, this kind of water control was necessary to support large populations throughout the year due to the scarcity of perennial surface water and the seasonal availability of rainfall. ③Some scholars argue that the concentration of water within the urban core of these sites provided a centralized source of political authority for Maya elites based largely on controlled water access. ④Such an argument is plausible; however, it is less useful for understanding the sociopolitical implications of water use and control in other, water-rich parts of the Maya region.47. The author of the passage implies which of the following about the political importance of the type of urban water management system described in the passage? ______

单选题. ①Was resource intensification—an increase in labor and time devoted to subsistence activities in order to increase food yields—by Dorset Paleo-Eskimos and Recent Indians on the island of Newfoundland simply a response to population pressure? ②Not exactly. ③On Newfoundland, population pressure did not result from a steadily growing resident population but, rather, from the arrival and lingering presence of new and significantly different populations. ④Newfoundland's hunter-gatherer populations—both resident and newcomer—adjusted to the presence of other populations through niche differentiation. ⑤Building on a tradition that emphasized marine resources, Dorset Paleo-Eskimos intensified their harvest of seals in response to the arrival of Recent Indians in the first few centuries A.D. ⑥Recent Indians who were more familiar with broad-based, interior-maritime adaptation, intensified this strategy to cope with the Dorset.41. According to the passage, which of the following resulted from the arrival of the Recent Indians? ______

单选题把0-15这16个数分别写在卡上放到一个盒子里，如果从这个盒子里无返回地取出卡片，问至少取出多少个数才能保证有两个卡片上的数目和是16?

单选题 Currently

单选题. ①Massive projectiles striking much larger bodies create various kinds of craters, including multi-ring basins–the largest geologic features observed on planets and moons. ②In such collisions, the impactor is completely destroyed and its material is incorporated into the larger body. ③Collison's between bodies of comparable size, on the other hand, have very different consequences: one or both bodies might be entirely smashed, with mass from one or both the bodies redistributed among new objects formed from the fragments. ④Such a titanic collision between Earth and a Mars-size impactor may have given rise to Earth's Moon. ①The Earth-Moon system has always been perplexing. ②Earth is the only one of the inner planets with a large satellite, the orbit of which is neither in the equatorial plane of Earth nor in the plane in which the other planets lie. ③The Moon's mean density is much lower than that of Earth but is about the same as that of Earth's mantle. ④This similarity in density has long prompted speculation that the Moon split away from a rapidly rotating Earth, but this idea founders on two observations. ⑤In order to spin off the Moon, Earth would have had to rotate so fast that a day would have lasted less than three hours. ⑥Science offers no plausible explanation of how it could have slowed to its current rotational rate from that speed. ⑦Moreover, the Moon's composition, though similar to that of Earth's mantle, is not a precise match. ⑧Theorizing a titanic collision eliminates postulating a too-rapidly spinning Earth and accounts for the Moon's peculiar composition. ⑨In a titanic collision model, the bulk of the Moon would have formed from a combination of material from the impactor and Earth's mantle. ⑩Most of the earthly component would have been in the form of melted or vaporized matter. ○11The difficulty in recondensing this vapor in Earth's orbit, and its subsequent loss to the vacuum of outer space, might account for the observed absence in lunar rocks of certain readily vaporized compounds and elements. ①Unusual features of some other planets might also be explained by such impacts. ②Mercury is known to have a high density in comparison with other rocky planets. ③A titanic impact could have stripped away a portion of its rocky mantle, leaving behind a metallic core whose density is out of proportion with the original ratio of rock to metal. ④A massive, glancing blow to Venus might have given it its anomalously slow spin and reversed direction of rotation. ⑤Such conjectures are tempting, but, since no early planet was immune to titanic impacts, they could be used indiscriminately to explain away in a cavalier fashion every unusual planetary characteristic; still, we may now be beginning to discern the true role of titanic impacts in planetary history.9. According to the passage, which of the following is true of the collisions mentioned in the highlighted sentence? ______

单选题. ①Because different mammalian species favor different environments, identifying and counting bones from prehistoric deposits in caves can reveal much about climatic changes. ②However, using large mammals' bones can be problematic. ③Some species, such as red deer, are very adaptable—at home both on open grassland and in thick woodland. ④Moreover, some large-animal bones may have traveled considerable distances before being discarded: both carnivores and humans can have large hunting territories and bring home large animals quite unlike those near their den or campsite. ⑤Consequently, the bones of the small mammals found within cave sediments provide a better index of climate change: they are generally more numerous, the species are more sensitive to environmental conditions, and few travel far within their short lives.39. The passage mentions which of the following as an obstacle to using animal bones to reconstruct past climate changes? ______

单选题Quantity A: p and q are two consecutive positive integers The remainder when the product of p, q is divided by 2Quantity B: 1

单选题有一个球从人行道上8米高的窗户处扔下，每一次反弹都是上一次下落距离的一半，求第五次反弹的高度?