单选题一个长方体形木盒子的长、宽、高分别为6，8，10；一个圆柱形罐头被放置在长方体形盒子中，问在所有的罐头中有最大体积罐头的底面半径是多少?

单选题. ①The occurrence of dense aggregations of the fruit-bearing tree Brosimum alicastrum on or near Maya ruin complexes in Central America was initially interpreted as evidence of ancient Maya silviculture, i.e., the stands were relics of orchards planted by the Maya. ②Later work, however, suggested that the stands resulted from the Artibeus bats that roost among the ruins. ③The bats fly to the forest, collect the fruit, bring it back to their roost, eat the fruit, and then discard the undamaged seed. ④The continual input of bat-dispersed seed has maintained the clumps of B. alicastrum around ruins for many hundreds of years. ①This observation, however, does not negate the possibility that B. alicastrum was used and managed by the Maya. ②In fact, if we examine the behavior, rather than the density or location, of these tree populations, we are presented with strong evidence of deliberate genetic improvement. ③This is especially notable in the B. alicastrum trees that cluster around the Maya ruins at Tikal in Guatemala: these trees' productivity is almost twice that of trees in Veracruz, Mexico, under almost identical environmental conditions.13. "The continual input of bat-dispersed seed" is mentioned in the passage as part of an explanation for ______

单选题18. The pepper Capsicum chinense grows as a native wild plant only in South America. Birds swallow the pepper's fruit whole, thereby providing the plant with its means of distributing seeds. Domesticated varieties of C.chinense grow in the Caribbean islands as well as in South America. Although it is unknown just when C.chinense was introduced into the islands, the introduction of the species was probably the result of human activity, because ______. Which of the following most logically completes the argument? ______

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

单选题There are 30 pairs of socks in a drawer, 60％ of the socks are red and the rest are blue. What is the minimum pairs of socks that must be taken from the drawer without looking in order to be certain th

单选题数列{a1，a2，…，an，…}，a1=5，a2=10，an+1=anaan-1，问第几项起就至少有5百万位数字?

单选题 ① When Earth formed 4.6 billion years ago

单选题7. A mouse's immune system generally rejects proteins different from those produced by that mouse. The immune system of a pregnant mouse does not, however, reject the mouse's fetuses, although the fetal tissue a fetus produces as it develops typically contains many such proteins. Some scientists hypothesize that the placenta surrounding the fetus physically blocks the mother's immune system. But others, noting that the placenta produces IDO, an enzyme that suppresses the immune system, hypothesize that IDO plays a crucial role in protecting the fetus. In order to choose between the two hypotheses, it would be most useful to determine which of the following? ______

单选题 ①For years

单选题. ①Scholars have tended to treat the ideas of American social reformer Jane Addams as unique, failing to compare them sufficiently those of other social activists and public intellectuals. ②Recent work, however, has situated her more thoroughly in the thinking and events of her time. ③For example, labor historians have usefully contextualized Addams' close work with labor unions in the 1890s. ④When Addams' interest in the workers' reform agenda is understood in relation to the history of trade unionism in Chicago and its impressive record of political action, her contribution emerges as far more cooperative than groundbreaking. ⑤Workers influenced her in ways not previously appreciated. ⑥Such contextualizing efforts make it possible to see what Addams learned from other reformers and what she contributed herself.7. The primary purpose of the passage is to ______

单选题There are 35 applicants applying for the position. 20 of them have experience, 13 of them are older than 25 years old, and 5 have no experience and are younger than 25 years old. How many of the appli

单选题How many positive integers n are there such that 30n is a divisor of 23×3×53?

单选题. ①African American painter Malvin Gray Johnson (1896-1934) grew up in urban environments, including New York City, but in 1934 visited and painted scenes from the small town of Brightwood, Virginia. ②Some critics have celebrated the Brightwood paintings, which depict a vibrant natural landscape and close-knit Black community, as Johnson's discovery of an "authentic" African American life in the rural South. ③This view, which reflects a common tendency to regard African American artists' imagery as unmediated documentation of direct experience, overlooks Johnson's interpretive thinking. ④In truth, Johnson's conceptualization of the South was largely formed before he left New York, where he had studied the French expressionist Paul Cézanne. ⑤Johnson's Brightwood paintings reflect Cézanne's stylistic influence and tendency to present rural life as an idyllic alternative to modern industrialism.49. The primary purpose of the passage is to ______

单选题33. Marine archaeologists recently discovered underwater in an ancient Mediterranean harbor several hundred ceramic objects, dating back approximately 4,000 years. Although any remnants of a ship's wooden frame would have long ago decayed, the quantity and variety of the ceramics discovered in the initial investigation led the archaeologists to hypothesize that they had discovered an approximately 4,000-year-old shipwreck. Which of the following, if true, gives the strongest support to the archaeologists' hypothesis? ______

单选题 Last year

单选题. ①Astronomers have had difficulty accounting for certain planets discovered outside our solar system. ②They are called hot Jupiters because each is similar in mass to Jupiter, the largest solar-system planet, but orbits its parent star at a fraction of the distance at which Earth, let alone Jupiter, orbits the Sun. ③In the standard, solar-system-based theory of planetary formation, such as a massive planet could not form so close to a star. ④So most attempts to explain a hot Jupiter's existence envision it forming farther away, then migrating inward. ⑤According to one hypothesis, the planet's gravitational field tugs on the protoplanetary disk of dust and gas from which it formed. ⑥The disk exerts its own gravitational tug, and this interplay of forces robs the planet of momentum in its orbital path, forcing it to spiral in toward the star. ⑦According to another hypothesis, the planet's gravitational field is so strong that it creates a groove in the disk, partitioning it into inner and outer regions; the resulting gravitational interactions between the planet and these regions cause the planet to lose orbital momentum and spiral inward. ⑧Another question remains: what prevents the planet from continuing its spiral until it collides with the star?29. The author of the passage mentions "Earth" primarily in order to ______

单选题If n is an integer greater than 2, which of the following CANNOT be all even integer?

单选题30. Although several ancient cultures practiced mummification, mummies from ancient Egypt are generally more well-preserved than mummies of similar antiquity from other cultures. One possible explanation for this difference is that the mummification techniques or materials used by ancient Egyptians were better than those of other cultures. A second, more likely, explanation is that the extremely dry climate of ancient Egypt was largely responsible, given that dryness promotes the preservation of organic remains generally. Which of the following provide the most support for the argument? ______