A
Even though human being has known asbestos(石棉)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(修屋顶的工人), 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 its surprising power to his customers. After putting on a pair of asbestos gloves, which looked much like ordinary work gloves, he took redhot 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 or carry 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(岩脉), 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 mined, the asbestos is heavy, just as you would expect a mineral to be. When it is separated, a strange thing happens: the rock breaks down into fine, soft, soapy fibres(纤维)．
Scientists do not know why the rock can be separated easily into threads(线), but they have found thousands of uses of this fireproof material, often the socalled “cloth of stone”．
短文介绍了耐火材料石棉在北美的开采过程及它的神奇的耐火作用。尽管人类早在几百年前就知道石棉，可是真正在北美开采是在160年前。
1．Which title best expresses the main idea of this passage?
A．Asbestos mined in Canada
B．Fireproof matter
C．A “wonder” mineral
D．A new roofing material
解析：标题判断题。短文主要介绍了石棉的神奇作用。故C最佳。
答案：C
2．Johns proved his ability as a salesman by ________.
A．going into roofing business
B．carrying asbestos from Italy
C．sending a trained scientist
D．showing the use of asbestos gloves
解析：细节理解题。根据 After putting on a pair of asbestos gloves...took redhot coals from the fireplace and played with them in his hands 可推知，他是用当场演示的方法来推销他的产品的。故答案为D。
答案：D
3．Which is the most important character of asbestos that the author wants to show us?
A．It is like thread. B．It feels soapy.
C．It burns easily. D．It is unusually heavy.
解析：推理判断题。根据When it is separated, a strange thing happens: the rock breaks down into fine, soft, soapy fibres(纤维)及 Scientists do not know why the rock can be separated easily into threads(线)，可以断定答案为A。
答案：A
4．The author's main purpose in writing this passage was to ________.
A．show the need for more scientists
B．compare asbestos with other minerals
C．increase the sales of asbestos
D．present facts about asbestos
解析：推理判断题。从短文中可以看出来作者写这篇文章只不过陈述事实而已。故答案为D。
答案：D
