The balance of nature is a very elaborate and delicate system of check
and countercheck. It is continually being altered as climates change, as new
organisms evolve, as animals or plants spread to new areas. But the alterations
have in the past, for the most part, been slow. whereas with the arrival of
civilized man, their speed has been multiplied much: from the evolutionary
time-scale, where change is measured by periods of ten or a hundred thousand
years, they have been transferred to the human time-scale in which centuries and
even decades count. Everywhere man is altering the balance of
nature. He is facilitating the spread of plants and animals into new regions.
Sometimes deliberately, sometimes unconsciously. He is covering huge areas with
new kinds of plants, or with houses, factories, slagheaps and other products of
his civilization. He gets rid of some species on a large scale, but favors the
multiplication of others. In brief, he has done more in five thousand years to
alter the biological aspect of the planet than has nature in five million
years. Many of these changes which he has brought about have
had unforeseen consequences. Who would have thought that the throwing away of a
piece of Canadian waterweed would have caused half the waterways of Britain to
be blocked for a decade? Or that provision of pot cacti for lonely settlers'
wives would have led to Eastern Australia being covered with forests of prickly
pears? Who would have predicted that the cutting down of
forests on the Adriatic coast, or in parts of Central Africa, could have reduced
the land to a semi-desert with the very soil washed away from the bare rock? Who
would have thought that improved communications would have changed history by
the spreading of disease-sleeping sickness into East Africa, measles into Ocean.
AIDS around the whole world? These are spectacular examples,
but examples on a smaller scale are everywhere to be found. We made a nature
sanctuary for rare birds, providing absolute security for all species; and we
may find that some common and hardy kind of birds multiplies beyond measure and
drive away the rare kinds in which we are particularly interested. We see, owing
to some little change brought about by civilization, the starting spread over
the English countryside in hordes. We improve the yielding capacities of our
cattle; and find that how they exhaust the pastures which were sufficient for
less demanding stock. We gaily set about killing the carnivores that disturb our
domestic animals, the hawks that eat our fowls and game-birds; and find that in
so doing we are also removing the brake that restrains the multiplication of
mice and other little rodents that gnaw away the farmers' profits.
单选题
The author's concern with the balance of nature, as evidenced by this
passage, is best defined as ______.
单选题
So far as the alterations of the balance of nature are concerned, man
______.
A. is somewhat more responsible than nature itself
B. plays a much greater role than nature itself
C. has done more than nature in recent years
D. is more likely to blame than nature
【正确答案】
B
【答案解析】[解析] 文章第二段最后一句提到，“In brief，he has done more in five thousand years to alter the biological aspect of the planet than has nature in five million years.”表明在对自然平衡的改变方面，人类比自然界所起的作用要大，即B项中的内容。通过这句话同样可以判断出A、C、D不正确。A中不应是“somewhat”，C中不应有“in recent years”，D中不应是“likely”，而是确实如此。
单选题
It can safely be inferred from the article that ______.
A. civilized man is No.1 enemy of nature
B. altering the balance of nature will definitely lead to man's extinction
from the planet
C. modem technology sometimes makes people's life worse rather than
better
D. most deserts and senti-deserts are due to the cutting down of
forests
单选题
The word "unforeseen" (Line 1) in Paragraph 3 means ______.
A. that have never been seen
B. that have never been experienced
C. that cannot be accepted
D. that cannot be expected
【正确答案】
D
【答案解析】[解析] unforeseen的词义一是可以从其本身的构词特征上着手，我们应该能够猜出foresee的意思是“预见”，那么unforeseen应该就是“难以预见的”。另一方面，我们可以从作者在下文中不断运用的“who would have thought predicted…”句式中猜测其义，这是一种虚拟表达方式，表示“谁能想得到或预见到……”。也就是说，作者所依据的例子都是一些事先想不到的或无法预见的后果。