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American black bears appear in a variety of colors despite their name. In the eastern part of their range, most of these bears have shiny black fur, but in the west they grow brown, red, or even yellow coats.     Even in the same litter (一窝幼崽）, both brown and black furred bears may be born.
Black bears are the smallest of all American bears, ranging in length from five to six feet, weighing from three hundred to five hundred pounds.  
  However, if attacked, most can climb trees and cover ground at great speeds. When angry or frightened, they are formidable(可怕的) enemies.
Black bears feed on leaves, herbs, fruit, berries, insects, fish, and even larger animals.    Unlike squirrels, woodchucks, and many other woodland animals, bears do not actually hibernate(冬眠). Although the bear does not eat during the winter months, sustaining itself from body fat, its temperature remains almost normal, and it breathes regularly four or five times per minute.
  They prefer to live in caves. Baby black bears are born in January or February after a gestation(怀孕) period of six to nine months, and they stay with their mother until they are fully grown or about one and a half years old. Black bears can live as long as thirty years in the wild, and even longer in some nature reserves.

A．To the north, the black bear is actually gray or white in color.

B．Black bears mate(交配) all year round.

C．One of the most interesting characteristics of bears, including the black bear, is their winter sleep.

D．Like all bears, the black bear is timid, clumsy, and rarely dangerous.

E. Bears often eat a lot of food before they hibernate in their caves.
F. Most black bears live alone, except during mating season.
G. Their eyes and ears are small and their eyesight and hearing are not as good as their sense of smell.