[单项选择]

Passage One
"A rolling stone gathers no moss (苔藓) ," but there is one living animal that does gather moss, the three-toed sloth (树獭) of South America. This slowest-moving member of the animal kingdom is so inactive that moss actually gathers on its body and turns it green strange as it seems!
Most of the sloth’s life is spent motionless, hanging upside down from a limb. And that is the way its hair grows. Long and coarse, the strands (串) from receptacles (花托) for the damp jungle algae (水藻) that turn the brown fur a mossy green. Actually this moss helps the animal survive because it serves as a per- fect camouflage against the leaf trees and hides the sloth from the jungle’s swift-moving hunters. The sloth would have little chance of survival on the ground. With long, curved claws hooked over the limb of a leafy tree, it spends the long hot hours during the day drowsing and eating. Inch by inch, it strips the leafy limbs bare and crawls
A. Wild Animals
B. Animal Kingdom
C. Moss Growth
D. The Lazy Animal