单选题 ①In recent decades

单选题Quantity A: k is an integer between 1 and 100, inclusive what is probability that k×k+1×k+2×k+3×k+4 is divisible by 20Quantity B: 1

单选题今年5月，上海某家汽车制造厂上线了人们期盼已久的新轿车，在这些轿车中，有20％是红色的，80％是蓝色的；有25％的车排放量是1.6升，有75％的车排放量是1.8升。如果在100辆轿车中有10辆车是红色并且排放量为1.6升，那么有多少辆车是蓝色并且排放量为1.8升?

单选题A是一个由5个不相同的正整数组成的集合，B是一个由4个不相同的正整数组成的集合，并且B是A的子集。问A、B的下面哪一个是不可能相同的?

单选题. ①Until around 1930 few United States Civil War historians paid much attention to Southerners who opposed the 1861-1865 secession from the United States by a confederacy of Southern states. ②Southern historians clung instead to a notion of the South's unanimity in the face of Northern aggression. ③Only when scholars such as Lonn decided to examine this side of the war did historian of the Confederacy begin to recognize the existence of Southerners loyal to the Union (Unionists). ④While these early historians of Southern dissent broke new ground, they also reproduced Confederate authorities' negative view of loyalists as shady characters driven by dubious motives. ⑤Even Tatum, who took a largely sympathetic attitude toward loyalists, tended to lump them into nebulous categories, offering broad generalizations that ignored the particulars of Unionists' identities and experiences. ①This early-twentieth-century historiography nonetheless represented the leading research on dissent in the South until the 1960s and 1970s. ②Spurred by the advent of social historical methods, a new generation of historians found Unionists interesting as manifestations of the Confederacy's internal weaknesses. ③Focusing on the Appalachian Mountain and upper South regions of the Confederacy, these scholars argued that there was a profound divide among Southern Whites between those who benefited economically from slave-run plantations and those who did not. ④One such historian was Escott, who emphasized regional and economic conflict among Southerners. ⑤Escott cast Unionists and other dissenters as mountaineers who could not, by reason of economic and social alienation, identify with the proslavery Southern cause. ⑥This theme has heavily influenced the work of subsequent scholars, who commonly place Unionists at the extreme end of a continuum of class-based Confederate disaffection that was ultimately responsible for the South's collapse. ⑦Because the driving force behind such inquiries into loyalist history has been a desire to explain Confederate ideology, politics, and defeat, emphasis has been placed on the ways loyalist Southerners diverged from the political and economic mainstream of Confederate nationalism. ①Only recently have some Civil War historians begun to make Unionists and their experiences, rather than the Confederate state, the center of inquiry. ②These scholars have done intensive community and local studies of dissenting groups that take into account a range of social and cultural, as well as military and political, factors at work on the Southern home front. ③Hoping to better understand who remained loyal to the Union during the war, these historians have sought to explain the Civil War's underlying character, dimensions, and impact in particular counties or towns, especially in the upper South and Appalachia. ④This relatively new trend has stressed the particular, delved into the complexities of political allegiances on the home front, and, as Sutherland notes, highlighted "the gritty experience of real people."42. The primary purpose of the passage is to ______

单选题 ①According to von Kárman

单选题. ①Many scholars have argued that government investment in manufacturing in the southern United States during the Second World War spurred a regional economic boom that lasted into the postwar period. ②But much of this investment went to specialized plants, many of them unsuitable for postwar production. ③Large-scale, wartime government funding led to a massive increase in the number and scale of munitions facilities. ④By the war's end, 216 munitions establishment costing more than $3.5 billion had been built, many of them located in the south. ⑤Indeed, according to one estimate, more than 70 percent of federally financed manufacturing construction capital in Alabama, Arkansas, Mississippi, and Tennessee went into munitions plants. ①Even in the northern regions with strong prewar manufacturing economics, these plants were difficult to deal with once the imperative of war had been removed. ②In the south few industrialists had the capacity or desire to transform these factories to a peacetime function. ③Accordingly, at war's end almost all of the southern munitions facilities were shut down, placed on standby, operated at a very low capacity, or converted to nonmanufacturing functions, usually storage. ④Although some reopened a few years later for use during the Korean War, the impact of the special plants on the South's postwar economy was marginal at best.35. The primary purpose of the passage is to ______

单选题 ①African American drama has, until recently

单选题gx=x2-x-1 and fx=gx+2Quantity A: f-1Quantity B: f1

单选题 ①Based on evidence from tree rings

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?