toefl写作范文下载之美国黑熊

　　American black bears

　　American black bears appear in a variety of colors despite their name. Inthe eastern part of their range, most of these brown, red, or even yellow coats.To the north, the black bear is actually gray or white in color. Even in thesame litter, both brown and black furred bears may be born.

　　Black bears are the smallest of all American bears, ranging in length fromfive to six feet, weighing from three hundred to five hundred pounds their eyesand ears are small and their eyesight and hearing are not as good as their senseof smell.

　　Like all bears, the black bear is timid, clumsy, and rarely dangerous, butif attacked, most can climb trees and cover ground at great speeds. When angryor frightened, it is a formidable enemy.

　　Black bears feed on leaves, herbs. Fruit, berries, insects, fish, and evenlarger animals. One of the most interesting characteristics of bears, includingthe black bear, is their winter sleep. Unlike squirrels, woodchucks, and manyother woodland animals, bears do not actually hibernate. Although the bear doesnot during the winter moths, sustaining itself from body fat, its temperatureremains almost normal, and it breathes regularly four or five times perminute.