单选题A.Atechnologytoproduceasubstancethatcanbemadeintosugar.B.Atechnologytoloadgarbageintoahugepressurecooker.C.Atechnologytoturnplantwastesandothergarbageintofuel.D.Atechnologytoproduceautomobilesoperatingonhigh-ethanolfuel.

单选题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℉. 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.

单选题

单选题 {{B}}Passage OneQuestions 26 to 28 are based on the passage you have just heard.{{/B}}

单选题{{B}}Passage Two{{/B}} When Mike Kelly first set out to build his own private space-ferry service, he figures his bread-and-butter business would be lofting satellite into high earth orbit. Now he thinks he may have figured wrong. "People were always asking me when they could go," says Kelly, who runs Kelly Space Technology, "I realized the real market is in space tourism." According to preliminary market surveys, there are 10,000 would-be space tourists willing to spend ＄1 million each to visit the final frontier. Space Adventures in Arlington have taken more than 130 deposits for a two-hour, ＄98,000 space tour tentatively set to occur by 2005. This may sound great, but there are a few hurdles. Putting a simple satellite into orbit--with no oxygen, life support or return trip necessary— already costs an astronomical ＄2,200/kg. And that doesn't include the cost of insuring rich and possibly litigious ( 爱打官司的 ) passengers. The entire group of entrepreneurs trying to comer the space-tourism market has between them "just enough money to blow up one rocket". The U.S. space agency has plenty of money but zero interest in making space less expensive for the little guys. So the little guys are racing to do what the government has failed to do: design a reusable launch system that's inexpensive, safe and reliable. Kelly Space's prototype looks like a plane that has sprouted rocket engines. Rotary Rocket in California has a booster with rotors to make a helicopter-style return to earth. The first passenger countdowns are still years away, but bureaucrats at the Federal Aviation Administration in Washington are already informally discussing flight regulations. After all, you can't be too prepared for a trip to that galaxy far, far away.

单选题Questions 1 and 2 will be based on the following news item.

单选题 Passage Three Questions 33 to 35 are based on the passage you have just heard.

单选题Why was iron unused for beams, columns, and girders prior to the early eighteenth century?

单选题According to the passage, Julian Huxley's theory suggests that______.

单选题According to Goldman Sachs, global water consumption is doubling every, ______ years. A. 30 B. 25 C. 20 D. 13

单选题[此试题无题干]

单选题[此试题无题干]

单选题[此试题无题干]

单选题