单选题Officials of the Sydney head of office will hold a conference to talk about goals for the next ten years.

单选题According to the passage, carbon dioxide serves which of the following functions for fire ants?

单选题JOHNNY APPLESEED 1 In 1801, a 26-year-old man named John Chapman wandered the sparsely populated "western country" that was still two years away from becoming the state of Ohio. Chapman had a simple purpose: wherever he found suitable soil, he planted apple seeds. To the settlers of the Ohio frontier, Chapman became known as Johnny Appleseed, a strange man who wore odd clothes and went barefoot. He was a pacifist in a time of warfare and brutality against the Indians, treating Indians and settlers alike with respect. He killed no animals and was a vegetarian. He even opposed pruning his apple trees because he did not want to cause them pain. 2 Chapman spent forty years wandering as Johnny Appleseed. Journeying by foot and canoe through Ohio and Indiana, he planted seeds, sold and gave away apple saplings, and exchanged knowledge of medicinal plants with Indians and settlers. He prepared the way for farms and towns by planting apple seeds in clearings along rivers and constructing simple wooden fences to keep animals out of his primitive orchards. 3 The agricultural development that Chapman anticipated was in fact marching across the eastern half of the continent at an ever-increasing pace. When Chapman started his "apple seeding" in 1801, the population of Ohio was 45,000, and ninety percent of the land was still covered with elm, ash, maple, oak, and hickory trees. By the time of Chapman's death in 1845, the state's population had reached two million, and more than forty percent of the land had been cleared of trees and converted to farms. Not until 1880 did the cutting of trees subside. By then, three-quarters of Ohio had been cleared, and people were becoming aware of the limits of expansion. Only then did they begin to take seriously the tree-loving ideas of Johnny Appleseed, who had become the subject of folk tales.

单选题(By) the late (twelve) century, stained glass (had emerged) in Europe (as an) integral part of Gothic architecture.

单选题Gold (can combined) with silver (in any) proportion, but alloys with 50 (to) 60 percent silver are (the strongest).

单选题The foundation of all other branches of mathematics is arithmetic, _ science of calculating with numbers.

单选题The Louisiana Purchase of 1803 increased the territory of the United States by approximate 846,000 square miles, practically doubling the area of the United States.

单选题When swollen by melting snow or heavy rain, some rivers routinely overflow its banks.

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单选题What was special about flint enamel?

单选题The word "Undoubtedly" in line I is closest in meaning to

单选题The (chemical element) chlorine is a corrosive, greenish-yellow gas (that) has (sharp) odor and (has) 21/2 times heavier than air.

单选题1 Alligators have no natural predators except humans. In fact, humans drove alligators to near extinction in many of their marsh and swamp habitats in North America. Hunters once killed large numbers of these animals for their meat and soft belly skin, which was used to make shoes, belts, and wallets. Between 1950 and 1960, hunters wiped out 90 percent of the alligators in Louisiana and greatly reduced the alligator population in the Florida Everglades. 2 In 1967 the federal government placed the American alligator on the endangered species list. In the next decade, protected by hunters and averaging about 40 eggs per nest, the alligator made a strong comeback. It was reclassified from endangered to threatened in Florida, Louisiana, and Texas, where the vast majority of the animals live. As a threatened species, it is still protected from excessive harvesting by hunters; however, limited hunting is allowed in some areas to keep the population from growing too large.

单选题The computer's complex circuitry is miniaturized inside silicon chips, wafer-thin silicon crystals with circuits electronic etched onto them

单选题During the 1850', reform movements _____temperance and the abolition of slavery gained strength in the United States.

单选题What does the passage mainly discuss? (a) Pasteur's influence on the development of the microscope. (b) The origin of the theory of spontaneous generation. (c) The effects of pasteurization on food. (d) Pasteur's argument against the theory of spontaneous generation.

单选题Astronauts receive extensive training to prepare themselves both physically and psychologically for complexity and rigor of a space mission.

单选题Listentopartofalectureinajournalismclass.Nowgetreadytoanswerthequestions.Youmayuseyournotestohelpyouanswer.

单选题Some marine invertebrates, (such as the. sea urchin and the starfish, (migrates) from deep water (to shallow) during spring and early summer (to spawn). A. such as the B. migrates C. to shallow D. to spawn

单选题There are about 350 species and subspecies of birds in danger of become extinct, with a large number of them, 117 in all, found on oceanic islands.