Question 1-9
The canopy ,the upper level of the trees in the rain forest, holds a plethora of climbing
mammals of moderately large size, which may include monkeys, cats, civets, and
porcupines. Smaller species, including such rodents as mice and small squirrels ,are not
line as prevalent overall in high tropical canopies as they are in most habitats globally.
(5) Small mammals, being warm blooded, suffer hardship in the exposed and turbulent
environment of the uppermost trees. Because a small body has more surface area per unit
of weight than a large one of similar shape, it gains or loses heat more swiftly. Thus, in
the trees, where shelter from heat and cold may be scarce and conditions may fluctuate, a
small mammal may have trouble maintaining its body temperature.
(10) Small size makes it easy to scramble among twigs and branches in the canopy for
insects, flowers, or fruit, but small mammals are surpassed, in the competition for food,
by large ones that have their own tactics for browsing among food-rich twigs. The weight
of a gibbon (a small ape) hanging below a branch arches the terminal leaves down so that
fruit-bearing foliage drops toward the gibbon’s face. Walking or leaping species of a
(15) similar or even larger size access the outer twigs either by snapping off and retrieving the
whole branch or by clutching stiff branches with the feet or tail and plucking food with
their hands.
Small climbing animals may reach twigs readily, but it is harder for them than for large
climbing animals to cross the wide gaps from on tree crown to the next that typify the
(20) high canopy. A macaque or gibbon can hurl itself farther than a mouse can: it can achieve
a running start, and it can more effectively use a branch as a springboard, even bouncing
on a climb several times before jumping. The forward movement of a small animal is
seriously reduced by the air friction against the relatively large surface area of its body.
Finally, for the many small mammals that supplement their insect diet with fruits or seeds
(25) an inability to span open gaps between tree crowns may be problematic, since trees that
yield these foods can be sparse. 【題組】4. According to paragraph 2, which of the
following is true about the small mammals in
the rain forest?
(A) They have body shapes that are adapted to
life in the canopy.
(B) They prefer the temperature and climate of
the canopy to that of other environments.
(C) They have difficulty with the changing
conditions in the canopy.
(D) They use the trees of the canopy for shelter
from heat and cold.
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