2. 外语
  3. " Copy the ways of nature," we were told. Yes, copy nature — for everything comes directly or indirectly from natural things. Of

" Copy the ways of nature," we were told. Yes, copy nature — for everything comes directly or indirectly from natural things. Of

admin2016-11-21  68
问题     " Copy the ways of nature," we were told. Yes, copy nature — for everything comes directly or indirectly from natural things. Often we have to put our knowledge to work, "treating" nature’s materials so as to make them serve our purposes better. We could, certainly, take the skin from a dead animal and at once make a pair of shoes with it: but they wouldn’t be very good shoes. For ourpurpose it is better first to treat the skin with chemicals that turn it into leather.
    Until fairly recently our efforts to copy nature’s methods of manufacture were not very successful. Up to about 1950 only animal skins provided material for good shoes. Clothes had to be made of cotton from the cotton plant or of wool from sheep. The only kind of rubber we had came from the rubber tree. Close study of all such useful materials showed that their chemistry was simple in some ways, most complicated in others. Their basic chemicals are plentiful — and surprisingly similar: that is the simple part. It is the arrangement of their atoms in groups, and the way these groups are stung together in long "chains", that is so complicated. Nature’s methods of combing atoms are what make her materials so varied and so suited to her purposes.
    From about 1930 chemists worked hard at the job of getting groups of atoms to combine in long chains. The "raw materials" they used were mainly the gases from coal and later from oil: and the chief means employed were heat and pressure. Some gases proved very active, combing readily, and combing with other gases too. The experiments were successful. A number of "new" materials were made.
    Nylon was one of these new materials: nylon stockings first appeared in 1939. Other kinds of plastics followed — some in the form of soft thread(for clothing), strong hair-like threads(for brushes), glass-like material(for bottles)... All were man-made materials, man-made for man’s purposes, not for Nature’s. And because man made them, he could vary them to suit each new purpose as it arose. One of the gases is the starting material for a kind of rubber that, when used in motorcar tyre, prevents the tyres from slipping easily on wet roads. The plastics industry is no longer new. It has grown into the giant petrochemical industry, producing for our needs not only plastics but a wide range of cleaning materials, paints, fertilizers ... the list is long and growing longer. Nature is beginning to look like a slow and limited manufacturer.
According to the writer, nylon and other plastics______.
选项 A、are a lot cheaper
B、are easily made
C、are suitable for special purposes
D、are not slippery on wet roads
答案C
解析 事实细节题。根据第五段的一All were man-made materials，man-made for man’s purposes，一as it arose可以看出答案是C。
转载请注明原文地址:https://kaotiyun.com/show/pQJK777K
0

专业英语四级

相关试题推荐
随机试题
最新回复(0)