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【单选题】
Geographers and historians have traditionally held the view that Antarctica was first sighted around 1820, but some sixteenth-century European maps show a body that resembles the polar landmass, even though explorers of the period never saw it. Some scholars, therefore, argue that the continent must have been discovered and mapped by the ancients, whose maps are known to have served as models for the European cartographers. Which of the following, if true, is most damaging to the inference drawn by the scholars?A.
The question of who first sighted Antarctica in modern times is still much debated, and no one has been able to present conclusive evidence.
B.
Between 3,000 and 9,000 years ago, the world was warmer than it is now, and the polar landmass was presumably smaller.
C.
There are only a few sixteenth-century global maps that show a continental landmass at the South Pole.
D.
Most attributions of surprising accomplishments to ancient civilizations or even extraterrestrials are eventually discredited or rejected as preposterous.
E.
Ancient philosophers believed that there had to be a large landmass at the South Pole to balance the northern continents and make the world symmetrical.
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【多选题】以下关于高速断路器说法正确的是（ ）
A.
高速断路器又称为HSCB
B.
在升弓到架空线或从架空线上降弓之前，必须打开高速断路器。
C.
在“紧急停车”的情况下，高速断路器将跳脱。司机使用司机室内的任何一个紧急按钮均可以将其启动。
D.
在出现严重干扰的情况下，如过电流、逆变器故障或线路短路时，使用闸刀开关，可以切断特定的受电弓到相关的高速断路器(HSCB以及VVVF逆变器之间的电源。
【多选题】以下关于真空断路器说法正确的是( )
A.
真空断路器利用高真空作为内绝缘和灭弧介质。
B.
真空断路器灭弧室里高真空、其气体稀薄、气体分子少,分子的平均自由行程大,发生碰撞的机率很小,即真空间隙的绝缘强度远比空气高。
C.
真空断路器灭弧室由于真空的原因,弧柱中的带电质点扩散的速度较慢,所以电弧很容易熄灭。
D.
真空断路器灭弧室由于真空的原因,弧柱中的带电质点扩散的速度较快,所以电弧很容易熄灭。
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