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问题 单项选择题

肌红蛋白是肌肉中带氧的球蛋白。下列哪个氨基酸最可能位于该分子的内部

A．精氨酸

B．谷氨酸

C．天冬氨酸

D．缬氨酸

E．赖氨酸

答案

参考答案：D

单项选择题

As Oil Declines, So does America


More than 100 years ago, America’s first great economic (26) abroad was spearheaded by its giant oil companies, notably John D. Rockefeller’s Standard Oil Company. These companies (27) powerful beachheads in Mexico and Venezuela, and later in parts of Asia, North Africa and, of course, the Middle East. (28) they became ever more dependent on the extraction of oil in distant lands, American foreign policy began to be (29) around acquiring and protecting US oil concessions in major (30) areas.
With World War Ⅱ and the Cold War, oil and US national (31) became thoroughly intertwined. After all, the United States had prevailed over the Axis (32) in significant part because it possessed vast reserves of domestic petroleum, while Germany and Japan lacked them, depriving their forces of vital (33) supplies in the final years of the war. As it happened, though, the United States was using up its domestic (34) so rapidly that, even before World War Ⅱ was over, Washington (35) its attention to finding new overseas sources of crude oil that could be (36) under American control. As a result, Saudi Arabia, Kuwait and a host of other Middle Eastern producers would become key US oil suppliers (37) American military protection.
There can be (38) question that, for a time, American domination of world oil production would prove a potent source of economic and military power. (39) World War Ⅱ, an abundance of cheap US oil spurred the (40) of vast new industries, including civilian air travel, highway construction, a (41) of suburban housing and commerce, mechanized agriculture, and plastics.

A. deployB. restC. act D. spread

Abundant oil also underlay the global expansion of the country’s (42) power, as the Pentagon defended the world while becoming one of the planet’s great oil guzzlers. Its global dominion came to (43) on an ever-expanding array of oil-powered ships, planes, tanks and missiles. As long as the Middle East—and especially Saudi Arabia—served essentially as an American gas station and oil (44) a cheap commodity, all this was relatively painless. That is why the use of military force has been a (45) of American foreign policy since 1987.
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单项选择题

血瘀疼痛的特点是( )

A．掣痛
B．灼痛
C．胀痛
D．冷痛
E．刺痛
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