2. 外语
  3. Humans are forever forgetting that they can’t control nature. Exactly 20 years ago, a Time magazine cover story announced that "

Humans are forever forgetting that they can’t control nature. Exactly 20 years ago, a Time magazine cover story announced that "

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问题    Humans are forever forgetting that they can’t control nature. Exactly 20 years ago, a Time magazine cover story announced that "scientists are on the verge of being able to predict the tome, place and even the size of earthquakes." The people of quake-ravaged Kobe learned last week how wrong that assertion was.
   None of the methods conceived two decades ago has yet to discover a uniform warning signal that preceded all quakes, let alone any sign that would tell whether the coning temblor is mild or a killer. Earthquake formation can be triggered by many factors, says Hiroo Kanamori, a seismologist at the California Institute of Technology, so, finding one all-purpose warning sign is impossible. One reason: Quakes start deep in the earth, so scientists can’t study them directly. If a quake precursor were found, it would still be impossible to warn humans in advance of all dangerous quakes, places like Japan and California are riddled with hundreds, if not thousands, of minor faults.
   Prediction would be less important if scientists could easily build structures to withstand tremors. While seismic engineering has improved dramatically in the past 10 to 15 years, every new quake reveals unexpected weaknesses in "quake-resistant" structures, says Terry Tullis, a geophysicist at Brown University. In Kobe, for example, a highway that opened only last year was damaged. In the Northridge earthquake, in the other hand, well-built structures generally did not collapse...
   A recent report in science adds yet more anxiety about life on tile faulty lines. Researchers ran computer simulations to see how quake-resistant buildings would fare in a moderate-size temblor, taking into account that much of a quake’s energy travels in a large "pulse" of focused shaking. The results: Both steel-frame buildings and buildings that sit on insulating rubber pads suffered severe damage.
   More research will help experts design stronger structures and possibly find quake precursors. But it is still a certainty that the next earthquakes will prove once again that every fault cannot be monitored and every highway cannot be completely quake-proofed.
What does the word "precursor" in the context in Para. 3 mean?
选项 A、A man that may come before the happening of an earthquake.
B、The leading actor that may cause a series of events to occur.
C、An meaningful sign that indicates some would-be happenings.
D、An event that may have symbolic or significant nature.
答案C
解析 本题为词义辨析题。考生可以在上下文中得到提示。首先提到了“so， finding one all-purpose warning sign is impossible．”紧接着下文提到，即使找到了a quake precursor，还是很难对所有危险的地震做出预警。可见，在这里precursor 意为a meaningful sign 比较合适。
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