It is hard to track the blue whale, the ocean’s largest creature, which has almost been killed off by commercial whaling and is

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问题     It is hard to track the blue whale, the ocean’s largest creature, which has almost been killed off by commercial whaling and is now listed as an endangered species. Attaching radio devices to it is difficult, and visual sightings are too unreliable to give real insight into its behavior.
    So biologists were delighted early this year when, with the help of the Navy, they were able to track a particular blue whale for 43 days, monitoring its sounds. This was possible because of the Navy’s formerly top-secret system of underwater listening devices spanning the oceans.
    Tracking whales is but one example of an exciting new world just opening to civilian scientists after the cold war as the Navy starts to share and partly uncover its global network of underwater listening system built over the decades to track the ships of potential enemies.
    Earth scientists announced at a news conference recently that they had used the system for closely monitoring a deep-sea volcanic eruption (爆发) for the first time and that they plan similar studies.
    Other scientists have proposed to use the network for tracking ocean currents and measuring changes in ocean and global temperatures.
    The speed of sound in water is roughly one mile a second—slower than through land but faster than through air. What is most important, different layers of ocean water can act as channels for sounds, focusing them in the same way a stethoscope (听诊器) does when it carries faint noises from a patient’s chest to a doctor’s ear. This focusing is the main reason that even relatively weak sounds in the ocean, especially low-frequency ones, can often travel thousands of miles. (283 words)
It can be inferred from the passage that______.

选项 A、new radio devices should be developed for tracking the endangered blue whales
B、blue whales are no longer endangered with the use of the new listening system
C、opinions differ as to whether civilian scientists should be allowed to use military technology
D、military technology has great potential in civilian use

答案D

解析 本题属于推理判断题。第一段最后一句话谈到:“Attaching radio devices to it is difficult,and visual sightings are too unreliable…”(给蓝鲸加上无线电装置是困难的,而且视觉景象是不可靠的……);故A可以排除。文中第一段谈到:“It’s hard to track blue whale…which has almost been killed of by commercial whaling and is now listed as an endangered species.”(很难观测到蓝鲸……它几乎全部被商业捕鲸杀尽,现在已列入濒危物种名单)故可以判定,鲸鱼濒危,是由于捕杀,而跟追踪技术无关,故排除B。文中讲到民用科学家准备使用海军探测技术,没有谈到对于是否运用有分歧,故排除C。那么,就只有D“军事技术在民用方面有潜力很大”为正确答案了。
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