Military drones already fly frequent missions and civilian operations using unmanned aircraft are coming. Drivcrlcss cars are cl

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问题     Military drones already fly frequent missions and civilian operations using unmanned aircraft are coming. Drivcrlcss cars are clocking up thousands of test miles. So why not let remote-controlled ships set sail without a crew? Indeed, the maritime industry has started to think about what would be required to launch a latter-day Marie Celeste.
    Ships, like aircraft and cars, are increasingly controlled by electronic systems, which makes automation easier. The bridges of some modern vessels are now more likely to contain computer screens and joysticks than engine telegraphs and a giant ship’s wheel. The latest supply ships serving the offshore oil and gas industry in the North Sea, for instance, use dynamic positioning systems which collect data from satellites, gyrocompasses, and wind and motion sensors to automatically hold their position when transferring cargo to and from platforms, even in the heaviest of swells.
    However, as is also the case with pilotless aircraft and driverless cars, it is not so much a technological challenge that has to be overcome before autonomous ships can set sail, but regulatory and safety concerns. As in the air and on the road, robust control systems will be needed to conform to existing regulations.
    The maritime industry is interested in crewless ships for two reasons. The first is safety. Most accidents at sea are the result of human error, just as they are in cars and planes. So, if human operators are replaced by sophisticated sensors and computer systems, autonomous vessels should, in theory, make shipping safer.
    The second reason is, of course, cost. It is becoming increasingly difficult to sign up competent crew prepared to spend months away at sea. Moreover, some voyages are likely to get even longer for ships carrying non-urgent cargo. By some accounts, a 30% reduction in speed by a bulk carrier can save around 50% in fuel. This means slower steaming could provide big savings in fuel costs, but it would be at the expense of increased expenditure on crew for these longer voyages, both in wages and for the "hotel" facilities required on board. Removing the crew, though, also removes the need for their accommodation and its associated equipment, like heating and plumbing. And that provides room to carry more cargo.
Ships with crew are more costly mainly because of______.

选项 A、pay and accommodation for sailors
B、hotel facilities needed on board
C、expenditure on more fuels
D、heating and plumbing

答案A

解析 根据题干中的ships with crew,costly等词定位到第五段。答案来自中间一句:...increased expenditure on crew for these longer voyages,both in wages and for the“hotel”facilitiesrequired on board.其中的both in wages and for the“hotel”facilities required on board为答案所在。选项[B]的hotel facilities needed on board只是部分答案,不完整,故该项错误。选项[C]不是主要因素,也不在答案句中出现,可以排除。选项[D]的heating and plumbing也是下文提到的内容,只有[A]项吻合。其中pay“工资”=wages“薪水”;accommodation forsailors“船员的食宿”=hotel facilities required on board“船上所需的住宿设施”,故[A]为本题答案。
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