二○○○年下半年全國(guó)高等教育自學(xué)考試英語(yǔ)(一)試卷3

字號(hào):

Passage Two Questions 26 to 30 are based on the following passage. Around the
    world two thirds of the people are farmers. Most of them engage in subsistence
    farming. This means that they raise plants and animals to furnish their families
    with food and other supplies. They consume their varied output and have little
    to sell or to trade for other goods. Subsistence farms were common in the United
    States at on time, but there are few such farms today. Two thirds of American
    farmers practice commercial farming. Commercial farms produce about 97 per cent
    of the country’s agricultural goods. These farms are operated much like other
    industries. The members of the farm family produce the commodities(商品)that will
    be sent to the market. They sell their products and buy the things they need.
    Some commercial farms are big factories in the field. They may be owned by company
    or by an individual as an investment. Most American farms, however, are still
    operated by families. A farmer may own or rent his land. In a country as large
    as the United States, farms vary widely in climate, land surface, soil, water
    supply, convenience to market, and other characteristics. Different regions may
    have different kinds of specialized farms. Specialized farmers concentrate on
    the kind of farming best suited to the land and climate, to their technical skills,
    and to the money they invest in the farm. However, no region is limited to a single
    type of farm. Indeed few farms are limited to one crop or commodity. Where out
    put is varied and no one kind of crop or commodity produces more than half of
    a farm’s income, it is classified as a general farm. The general farmer grows
    varied crops to use the efferent kinds of soils or surfaces on his land and to
    employ his time and machinery most efficiently. 26.Subsistence farmers ______.
    [A]grow crops for their families’ own use [B]sell a lot of their products for
    money [C]trade their varied out put for other goods [D]use their agricultural
    products as commodities 27.Subsistence farms ______. [A]are very popular in the
    United States now [B]are still common in many parts of the world [C]consist of
    two thirds of the total number of the farms in the world today [D]used to be the
    major form of farming in the world 28.American commercial farms ______. [A]furnish
    the country with two thirds of the food its people need [B]are run in much the
    same way as other industries [C]are all owned by different companies [D]never
    rent their land for farming 29.Aspecialized farm is characterized by ______.
    [A]its especially large size [B]its independence of the market [C]its
    concentration on a single type of farming [D]tits special way of operation 30.A
    farm is classified a general if ______. [A]more than half of its income comes
    from varied crops [B]it is limited to a single type of farm [C]it employs different
    kinds of machines [D]the soils or surfaces of its land are used most efficiently
     Passage Three Questions 31 to 35 are based on the following passage. No one knows
    for sure why birds migrate(定期遷徙).One theory of migration says that ancient
    birds of the northern part of the earth were forced southward during the Ice Age,
    when ice covered large parts of Europe, Asia and North America. As the ice melted,
    the birds came back to their homelands, spent the summer, and then went south
    again in winter. Gradually, these comings and goings became habits, and birds
    now migrate though much of the ice has gone. Another theory proposes that the
    ancient home of all modern birds was the tropic areas. There lived so well that
    the region became overcrowded. Many species had to move northward. During the
    summer, these birds found plenty of room and food. In winter, however, food became
    scarce and they had to return to the south. A newer theory is that increasing
    daylight stimulates certain glands(腺)in the bird’s body and prepares it for
    migration. One scientist is able to make birds migrate in midwinter by ex posing
    them for two months to artificial daylight. Recoveries of marked birds indicate
    that they fly north as soon as they are set free. The conclusion is that the urge
    to migrate is determined by changes in the bird’s body which take place under
    seasonal changes in the length of daylight. This theory would account for the
    fact that not all birds migrate at the same time. Each species seems to have its
    own schedule. The theory would also account for the regular time and routes of
    migration. Birds arrive at a given place year after year. Unfavorable weather
    delays them only a few days. Total hours of daylight, rather than weather, start
    them on the way. How birds find their way to the same place year and why they
    follow their own particular route are still mysteries. They evidently do not
    follow known landmarks(地面標(biāo)志),for many young birds migrate alone without the
    help of experienced adults.
    31.We can conclude from the first paragraph that
    ______.
    [A]during the Ice Age, the whole Europe was covered with ice
    [B]the south
    used to be the homelands of all birds
    [C]scientists can confidently explain why
    birds migrate now
    [D]migration of birds can be explained by the change of ice
    on earth
    32.The birds mentioned in the third paragraph fly north in midwinter
    because ________.
    [A]they are specially trained by a scientist
     [B]they are affected by seasonal changes
     [C]there is a change in their body temperature
    [D]they are exposed to extra daylight
    33.The phrase "account for" (line2,Para.4)most probably means _______.
    [A]indicate [B]explain [C]prove [D]provide
    34.Which of the following can NOT be inferred from the passage?
    [A]Birds do not migrate at the same time.
    [B]Birds usually follow regular routes
    of migration.
    [C]Each species has a special reason for migration.
    [D]Birds migrate
    to their own particular places every year.
    35.The best title for the passage is ______.
    [A]Different Accounts of Migration
    [B]Migration and Weather
    [C]New
    Discovery of Bird Migration
    [D]Routes of Bird Migration