2016年托福閱讀強化模擬試題(二)

        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

　　(15) leaping species of a 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

　　(20) typify the 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 limb 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

　　(25) diet with fruits or seeds, an inability to span open gaps between tree crowns may be

　　problematic, since trees that yield these foods can be sparse.

　　2. Which of the following animals is less common in the upper canopy than in other environments?

　　(A) Monkeys

　　(B) Cats

　　(C) Porcupines

　　(D) Mice

　　答案：D