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【单选题】

Humans are forever forgetting that they can’t control nature. Exactly 20 years ago, a magazine cover story announced that "scientists are on the verge of being able to predict the time, place and even the size of earthquakes". The people of quake-ruined Kobe learned last week how wrong that assertion was.
None of the methods praised two decades ago have succeeded. Even now, scientists have yet to discover a uniform warning signal that precedes all quakes, let alone any sign that would tell whether the coming quake is mild or killer. Earthquake formation can be triggered by many factors, says Hiroo Kanamori, a seismologist (地震学家) at the California Institute of Technology. So, finding one all-purpose warning sign is impossible. One reason: Quakes start deep in the earth, so scientist can’t study them directly.
If a quake precursor (预兆) were found, it would still be impossible to warn humans in advance of all erous quakes. Places like Japan and California are filled with hundreds, if not thousands, of minor faults. It is impossible to place monitoring instruments on all of them. And these inconspicuous sites can be just as deadly as their better-known cousins like the San Andreas. Both the Kobe and the 1994 Northridge quakes occurred on small faults.
Prediction would be less important if scientists could easily build structures to withstand every new quake reveals unexpected weaknesses in "quake-resistant" structure, says Terry Tullis, a geophysical at Brown University. In Kobe, for example, a highway that opened only last year was damaged.
In the Northridge earthquake, on the other hand, well-built structures generally did not collapse. But engineers have since found hidden problems in 120 steel-frame buildings that survived. Such structures are supposed to sway with the earth rather than crumple (崩溃). They may have swayed, but the quake also unexpectedly weakened the joints in their steel skeletons. If the shaking had been longer or stronger, the buildings might have collapsed.
A recent report in Science adds yet more anxiety about life on the fault lines. Researchers can computer simulations to see how quake-resistant buildings would fare in a moderate-size tremor, 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 pressures. But it is still a certainty that the next earthquake will prove once again that every fault cannot be monitored and every highway cannot be completely quake-proofed.
According to the passage, quakes ______.

A.
can in no way be studied fully
B.
can be warned of beforehand
C.
can trigger minor faults
D.
on small faults cannot possibly be as deadly as those best known quakes
题目标签:地震学崩溃
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【多选题】电力系统崩溃,指()。

A.
电压崩溃
B.
电网瓦解
C.
频率崩溃
D.
动态稳定破坏

【单选题】出现电压崩溃的最主要原因是()。

A.
A、有功功率严重不足
B.
B、无功功率严重不足
C.
C、电压等级过低
D.
C、出现了严重的短路故障

【单选题】产生系统电压崩溃的原因为()。

A.
无功功率严重不足;
B.
有功功率严重不足;
C.
系统受到小的干扰;
D.
系统发生短路。

【单选题】哪项为布雷顿森林体系崩溃的本质原因?()

A.
特里芬难题的存在
B.
国际协调能力有限
C.
发达国家通货膨胀程度差异
D.
发达国家国际收支极端不平衡