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  3. You never see them, but they’re with you every time you fly. They record whe

You never see them, but they’re with you every time you fly. They record whe

游客2024-02-14  5
问题     You never see them, but they’re with you every time you fly. They record where you’re going, how fast you’re traveling and whether everything on your airplane is functioning normally. Their ability to withstand almost any disaster makes them seem like something out of a comic book. They’re known as the black box.
    When planes fall from the sky, as a Yemeni airliner did on its way to the Comoros Islands in the Indian Ocean June 30, 2009, the black box is the best bet for identifying what went wrong. So when a French submarine (潜水艇) detected the device’s homing signal five days later, the discovery marked a huge step toward determining the cause of a tragedy in which 152 passengers were killed.
    In 1958, Australian scientist David Warren developed a flight-memory recorder that would track basic information like altitude and direction. That was the first model for a black box, which became a requirement on all U. S. commercial flights by 1960. Early models often failed to withstand crashes, however, so in 1965 the device was completely redesigned and moved to the rear of the plane—the area least subject to impact—from its original position in the landing wells (起落架舱). That same year, the Federal Aviation Authority required that the boxes, which were never actually black, be painted orange or yellow to aid visibility.
    Modern airplanes have two black boxes:  a voice recorder, which tracks pilots’ conversations, and, a flight-data recorder, which monitors fuel levels, engine noises and other operating functions that help investigators reconstruct the aircraft’s final moments. Placed in an insulated (隔绝的) case and surrounded by quarter-inch-thick panels of stainless steel, the boxes can withstand massive force and temperatures up to 2,000°F.  When submerged, they’re also able to emit signals from depths of 20,000 ft. Experts believe the boxes from Air France Flight 447, which crashed near Brazil on June 1, 2009, are in water nearly that deep, but statistics say they’re still likely to turn up. In the approximately 20 deep-sea crashes over the past 30 years, only one plane’s black boxes were never recovered.
[br] What do many African-Americans write about in their blogs?
选项 A、Whether Michelle can live up to the high expectations of her fans.
B、How Michelle should behave as a public figure.
C、How proud they are to have a black woman in the White House.
D、What Michelle should do as wife and mother in the White House.
答案 C
解析 细节题。根据题目定位到文中第三段第三句Early models often failed to withstand crashes，however, so in 1965 the device was completely redesigned…(然而早期的模型通常都不能抵抗碰擅，因此在1965年这个仪器被重新设计……)可知早期模型容易在碰撞中受损伤是重新设计的原因．因此选C。
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