单选题. ①Seeding a forest with nonnative species after a fire can impede native plant regeneration and spread invasive species in vulnerable fire-affected soils. ②Moreover, native seed sources are almost always sufficient for early nature reestablishment of native species, so planting should be considered only when natural regeneration is unlikely. ③Replanting dense stands of fast-growing conifers—a common postfire management practice—truncates the biologically rich early stage of ecological succession and can increase the severity of future fires. ④Other treatments should be carefully scrutinized for their potential to spread noxious weeds. ⑤For instance, straw much applied extensively to reduce erosion after the 2002 Hayman Fire in Colorado was contaminated with cheatgrass, an invasive grass difficult to control or eradicate once established.9. According to the passage, which of the following is a consequence of replanting an area with dense stands of fast-growing conifers after a fire? ______

单选题.①Madagascar's Mahafale cattle raisers have incorporated the prickly pear cactus into their pastoral economy, which depends on assisting their cattle through the dry season, when grass and water are scarce. ②Rather than relying on nomadism in the pursuit of water and pasture for their livestock, they have turned to cactus to keep stock alive. ③This has influenced the cattle raisers' way of life, particularly in terms of diet and mobility. ④Women harvest cactus for their families to eat. ⑤Male herders work cactus as a vegetable crop for cattle. ⑥For these benefits, pastoralists sow, prune, and shape prickly pear into living fences around their corrals. ⑦In doing so, these herders have become cactus cultivators, which has reduced their mobility.41. Select the sentence in the passage that tells how the prickly pear has affected the Mahafale diet.

单选题6. Recently an unusually high number of dolphins have been found dead of infectious diseases, and most of these had abnormally high tissue concentrations of certain compounds that, even in low concentrations, reduce dolphins' resistance to infection. The only source of these compounds in the dolphins' environment is boat paint. Therefore, since dolphins rid their bodies of the compounds rapidly once exposure ceases, their mortality rate should decline rapidly if such boat paints are banned. Which of the following, if true, most strengthens the argument? ______

单选题Quantity A: the standard deviation of 10, 45, 50, 55, 90Quantity B: the standard deviation of 10, 30, 50, 70, 90

单选题两个质数的和是40，求这两个质数的乘积的最大值是多少?

单选题Two dices each has six sides, which represent six values 1, 2, 3, 4, 5, 6 respectively. Cast the two dices and get two values, what is the probability of one value being 2 more than the other?

单选题In the figure above, the area of the circular region with center O is 16π, if AB=AC, what is the length of AB?

单选题13. Growing grapes in greenhouses containing air enriched with carbon dioxide increases crop yields, an effect that is enhanced when the growing temperature is also raised several degrees. Although enclosed cultivation is impractical in vineyards, increases in yields from grape cultivation in the open air can be expected because emissions from the burning of fossil fuels will almost certainly lead to an increase in the carbon dioxide content of atmospheric air over the next century. Which of the following, if true, most weakens the argument? ______

单选题 ①Historian F. W

单选题. ① Despite winning several prestigious literary awards of the day, when it first appeared, Alice Walker's The Color of Purple generated critical unease over puzzling aspects of its compositions. ②In what, as one reviewer put it, was "clearly intended to be a realistic novel," many reviewers perceived violations of the conventions of the realistic novel form, pointing out variously that late in the book, the narrator protagonist Celie and her friends are propelled toward a happy ending with more velocity than credibility, that the letters from Nettie to her sister Celie intrude into the middle of the main action with little motivation or warrant, and that the device of Celie's letters to God is especially unrealistic inasmuch as it forgoes the concretizing details that traditionally have given the epistolary novel (that is, a novel composed of letters) its peculiar verisimilitude: the ruses to enable mailing letters, the cache, and especially the letters received in return. ①Indeed, the violations of realistic convention are so flagrant that they might well call into question whether The Color of Purple is indeed intended to be a realistic novel, especially since there are indications that at least some of those aspects of the novel regarded by viewers as puzzling may constitute its links to modes of writing other than Anglo-European nineteenth-century realism. ②For example, Henry Louis Gates, Jr., has recently located the letters to God within an African American tradition deriving from slave narrative, a tradition in which the act of writing is linked to a powerful deity who "speaks" through scripture and bestows literacy as an act of grace. ③For Gates, the concern with finding a voice, which he sees as the defining feature of African American literature, links Celie's letters with certain narrative aspects of Zora Neale Hurston's 1937 novel Their Eyes Were Watching God, the acknowledged predecessor of The Color of Purple. ①Gates's paradigm suggests how misleading it may be to assume that mainstream realist criteria are appropriate for evaluating The Color of Purple. ②But in his preoccupation with voice as a primary element unifying both the speaking subject and the text as a whole Gates does not elucidate many of the more conventional structural features of Walker's novel. ③For instance, while the letters from Nettie clearly illustrate Nettie's acquisition of her own voice, Gates's focus on "voice" sheds little light on the place that these letters occupy in the narrative or on why the plot takes this sudden jump into geographically and culturally removed surroundings. ④What is needed is an evaluative paradigm that, rather than obscuring such startling structural features (which may actually be explicitly intended to undermine traditional Anglo-European novelistic conventions), confronts them, thus illuminating the deliberately provocative ways in which The Color of Purple departs from the traditional models to which it has been compared.19. The author of the passage would be most likely to agree with which of the following statements about the letters from Nettie to Celie? ______

单选题Mr. Smith deposited k dollars in a new account at an annual rate of 8 percent compounded quarterly, which of the following represents the value, in dollars, of the money in the account after 2 years?

单选题12+x2=256, where x≠4Quantity A: xQuantity B: 12

单选题 In a physical education class

单选题如果将小数0.123456789101112…无限不循环地把所有整数都列出来，那么小数点后第100位的数字是多少?

单选题 In most coastal regions

单选题有一数列Xk=4×k-3，k分别为7，8，9，4，5，6，10，11，12，问这些数的median等于多少?

单选题The regular price of a certain car is $10,000. If the price is discounted by 20 percent during the first week and the reduced price is then discounted by 5 percent during the next week, how much money

单选题Quantity A: the standard deviation of the odd numbers between 1 and 19 inclusiveQuantity B: the standard deviation of the even numbers between 2 and 22 inclusive