Although man has known asbestos for many hundreds of years, it was not until 160 years ago that it was mined for the first time

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问题     Although man has known asbestos for many hundreds of years, it was not until 160 years ago that it was mined for the first time on the North American continent. H. W. Johns, owner of a New York City Supply Shop for roofers, was responsible for the opening of that first mine.
    Mr. Johns was given a piece of asbestos which had been found in Italy. He experimented with the material and then showed is surprising powers to his customers. After putting on a pair of asbestos gloves, which looked much like ordinary work gloves, he took red-hot coals from the fireplace and played with them in his hands. How astonished the customers were to discover that he was not burned at all. You can well imagine that he had increasing business in asbestos roofing materials. However, because it was very expensive to transport them from Italy to the United States, Mr. Johns sent out a young scientist to seek a source nearer home. This young man found great vein, in the province of Quebec in Canada.
    Ever since 1881 Quebec has led the world in the production of this unusual mineral, which is made up of magnesium, silicon, iron, and oxygen. When it is separated, a strange thing happens; the rock breaks down into fine, soft, soapy fibers.
    Scientists do not know why the rock can be separated easily into threads, but they have found thousands of uses of this fireproof material, of the so-called "cloth of stone".
Which is the most important character of asbestos that the author wants to show us?

选项 A、It is like thread.
B、It feels soapy.
C、It burns easily.
D、It is unusually heavy.

答案A

解析 推理判断题。根据最后一段“Scientists do not know why the rock can be separated easily into threads, but they have found thousands of uses of this fireproof material, of the so-called ‘cloth of stone’. ”可知,作者最想让读者知道石棉的特点是它会被分解为棉线,所以B项、C项、D项错误。故选A。
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