8. If you want to buy really cheap second-hand books, you must ________.

A. venture in a most busy street

B. venture away from a busy street

C. take the risk of going to the beaten track

D. take the risk of wasting time to hunt them in less noticeable streets

9. The book sellers on Farringdon Road _________.

A. keep fine bookshops

B. keep only small bookshops

C. sell books on hand-carts

D. sell the same books as the bookshops on Charring Cross Road

10. The best topic for this passage is ________.

A. bookshops in London

B. the biggest bookshop in the world

C. Charring Cross Road

D. buying books in London

"A rolling stone gathers no moss (苔藓)," but there is one living animal that does gather moss - the three-toed sloth（树懒）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（大树枝）. And that is the way its hair grows. Long and coarse, the strands from receptacles for the damp jungle algae（藻类）turn the brown fur a mossy green. Actually this moss helps the animal survive because it serves as a perfect camouflage against the leafy 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 hooded 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 slowly down the trunk to find a new dining spot, but only at night.

In addition to looking rather like a vegetable, the sloth is a strict vegetarian. Running out of its favorite leaf is about the only thing that will make a sloth move. Then its appetite（食欲）may