题目内容
All whales fall into two groups, those with teeth and those without. Both beluga and dolphin belong to the suborder of toothed whales known as Odontoceti, along with porpoises, narwhals, pilot whales, killer whales and the largest toothed creature in the world, the sperm whale. Size differences among the Odontoceti are remarkable. A common porpoise will run only 4 or 5 feet in length and 300 pounds in weight; a sperm whale may be 10 times as long and 300 times as heavy. The beluga falls in between, weighing up to 2,000 pounds. And it does chirp. In fact, it makes a great variety of squeaking, whistling, and clicking sounds, which have earned it the name of sea canary.
The toothless, or baleen, whales belong to the suborder of Mysticeti. This is a group of generally large whales, formerly abundant in all the oceans of the world. Though reduced by hunting, most species are still found along the coasts of the United Stated and Canada. All but two of the Mysticeti reach 40 feet or more at maturity, with the blue whale running up to 100 feet and tipping the scales at up to 130 tons. This whale is by far the largest creature that has ever lived on earth, 4 times the weight of the largest dinosaur, 30 times that of an elephant.
With what topic is the passage mainly concerned？
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A．Because students need individual attention.B．Because students need to be stimulated.
His recommendation that Air Force (investigates) the UFO sighting (was) approved (by the mommission) and referred (to) the appropriate.
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One common mistake is choosing an occupation for 【B12】______ real or imagined prestige. Too many high-school students—or their parents for them—choose the professional field, 【B13】______ both the relatively small proportion of workers in the professions and the extremely high educational and personal 【B14】______ . The imagined or real prestige of a profession or a "White-collar" job is 【B15】______ good reason for choosing it as life's work. 【B16】______ , these occupations are not always well paid. Since a large proportion of jobs are in mechanical and manual work, the 【B17】______ of young people should give serious 【B18】______ to these fields.
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【B1】______
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