2015考研英语作文素材精选 (九)

考研网

考研英语作文是一个考察综合运用语言的部分，需要同学们运用逻辑思维下笔成文，因此，考前看一些意义深远、质量好的文章很有必要。以下是2015考研英语作文备考素材精选，请作参考。
   
     2015考研英语作文素材精选 (九)
    31 British Columbia
    British Columbia is the third largest Canadian provinces, both in area and
population. It is nearly 1.5 times as large as Texas, and extends 800
miles(1,280km) north from the United States border. It includes Canada's entire
west coast and the islands just off the coast.
    Most of British Columbia is mountainous, with long rugged ranges running
north and south. Even the coastal islands are the remains of a mountain range
that existed thousands of years ago. During the last Ice Age, this range was
scoured by glaciers until most of it was beneath the sea. Its peaks now show as
islands scattered along the coast.
    The southwestern coastal region has a humid mild marine climate. Sea winds
that blow inland from the west are warmed by a current of warm water that flows
through the Pacific Ocean. As a result, winter temperatures average above
freezing and summers are mild. These warm western winds also carry moisture from
the ocean.
    Inland from the coast, the winds from the Pacific meet the mountain
barriers of the coastal ranges and the Rocky Mountains. As they rise to cross
the mountains, the winds are cooled, and their moisture begins to fall as rain.
On some of the western slopes almost 200 inches (500cm) of rain fall each
year.
    More than half of British Columbia is heavily forested. On mountain slopes
that receive plentiful rainfall, huge Douglas firs rise in towering columns.
These forest giants often grow to be as much as 300 feet(90m) tall, with
diameters up to 10 feet(3m). More lumber is produced from these trees than from
any other kind of tree in North America. Hemlock, red cedar, and balsam fir are
among the other trees found in British Columbia.
    32 Botany
    Botany, the study of plants, occupies a peculiar position in the history of
human knowledge. For many thousands of years it was the one field of awareness
about which humans had anything more than the vaguest of insights. It is
impossible to know today just what our Stone Age ancestors knew about plants,
but form what we can observe of pre-industrial societies that still exist a
detailed learning of plants and their properties must be extremely ancient. This
is logical. Plants are the basis of the food pyramid for all living things even
for other plants. They have always been enormously important to the welfare of
people not only for food, but also for clothing, weapons, tools, dyes,
medicines, shelter, and a great many other purposes. Tribes living today in the
jungles of the Amazon recognize literally hundreds of plants and know many
properties of each. To them, botany, as such, has no name and is probably not
even recognized as a special branch of " knowledge" at all.
    Unfortunately, the more industrialized we become the farther away we move
from direct contact with plants, and the less distinct our knowledge of botany
grows. Yet everyone comes unconsciously on an amazing amount of botanical
knowledge, and few people will fail to recognize a rose, an apple, or an orchid.
When our Neolithic ancestors, living in the Middle East about 10,000 years ago,
discovered that certain grasses could be harvested and their seeds planted for
richer yields the next season the first great step in a new association of
plants and humans was taken. Grains were discovered and from them flowed the
marvel of agriculture: cultivated crops. From then on, humans would increasingly
take their living from the controlled production of a few plants, rather than
getting a little here and a little there from many varieties that grew wild- and
the accumulated knowledge of tens of thousands of years of experience and
intimacy with plants in the wild would begin to fade away.
    33 Plankton浮游生物. / 'plжηktэn; `plжηktэn/
    Scattered through the seas of the world are billions of tons of small
plants and animals called plankton. Most of these plants and animals are too
small for the human eye to see. They drift about lazily with the currents,
providing a basic food for many larger animals.
    Plankton has been described as the equivalent of the grasses that grow on
the dry land continents, and the comparison is an appropriate one. In potential
food value, however, plankton far outweighs that of the land grasses. One
scientist has estimated that while grasses of the world produce about 49 billion
tons of valuable carbohydrates each year, the sea's plankton generates more than
twice as much.
    Despite its enormous food potential, little effect was made until recently
to farm plankton as we farm grasses on land. Now marine scientists have at last
begun to study this possibility, especially as the sea's resources loom even
more important as a means of feeding an expanding world population.
    No one yet has seriously suggested that " plankton-burgers" may soon become
popular around the world. As a possible farmed supplementary food source,
however, plankton is gaining considerable interest among marine scientists.
    One type of plankton that seems to have great harvest possibilities is a
tiny shrimp-like creature called krill. Growing to two or three inches long,
krill provides the major food for the great blue whale, the largest animal to
ever inhabit the Earth. Realizing that this whale may grow to 100 feet and weigh
150 tons at maturity, it is not surprising that each one devours more than one
ton of krill daily.
    34 Raising Oysters
    In the oysters were raised in much the same way as dirt farmers raised
tomatoes- by transplanting them. First, farmers selected the oyster bed, cleared
the bottom of old shells and other debris, then scattered clean shells about.
Next, they "planted" fertilized oyster eggs, which within two or three weeks
hatched into larvae. The larvae drifted until they attached themselves to the
clean shells on the bottom. There they remained and in time grew into baby
oysters called seed or spat. The spat grew larger by drawing in seawater from
which they derived microscopic particles of food. Before long, farmers gathered
the baby oysters, transplanted them once more into another body of water to
fatten them up.
    Until recently the supply of wild oysters and those crudely farmed were
more than enough to satisfy people's needs. But today the delectable seafood is
no longer available in abundance. The problem has become so serious that some
oyster beds have vanished entirely.
    Fortunately, as far back as the early 1900's marine biologists realized
that if new measures were not taken, oysters would become extinct or at best a
luxury food. So they set up well-equipped hatcheries and went to work. But they
did not have the proper equipment or the skill to handle the eggs. They did not
know when, what, and how to feed the larvae. And they knew little about the
predators that attack and eat baby oysters by the millions. They failed, but
they doggedly kept at it. Finally, in the 1940's a significant breakthrough was
made.
    The marine biologists discovered that by raising the temperature of the
water, they could induce oysters to spawn not only in the summer but also in the
fall, winter, and spring. Later they developed a technique for feeding the
larvae and rearing them to spat. Going still further, they succeeded in breeding
new strains that were resistant to diseases, grew faster and larger, and
flourished in water of different salinities and temperatures. In addition, the
cultivated oysters tasted better!