根据下列材料回答下列各 题。 Auctions（拍卖)are public sales of goods，conducted by an offic

根据下列材料回答下列各 题。 Auctions(拍卖)are public sales of goods，conducted by an officially approved auctioneer．He asks the crowd assembled in the auction loom to make offers，or“bids”，for the variousitems on sale．He encourages buyers to bid higher figures，and finally names the highest bidderas the buyer of goods．This is called“knockingDown”the goods，for the bidding ends when theauctioneer bangs a small hammer on a table at which he stands，This is often set on a raisedplatform. called a rostrum． The ancient Romans probably invented sales by auction，and the English word comes fromthe Latin auction，meaning“increase”．The Romans usually sold in this way the spoils taken inWalt"：these sales were called“subusta”，meaning“under the spear”，a spear being stuck in theground a8 a signal for a crowd to gather．In the eighteenth and nineteenth centuries goods wereoften sold'by the candle'，a short candle was lit by the auctioneer；and bids could be made whileit stayed alight． An auction is usuallv advertised beforehand with full particulars of the articles to be soldand where and when they can be viewed by possible buyers．If the advertisement cannot givefullDetails．catalogues are printed，and each group of goods to be sold together，called a“lot”，is usually given a number．The auctioneer need not begin with lot l and continue in numericalorder；he may wait until he registers the fact that certain Dealers are in the room and then produce the lots they are likely to be interested in．The auctioneer's services are paid for in the form. of a percentage of the price the goods are sold for．The auctioneer therefore has a Directinterest in pushing up the bidding as high as possible． Practicaly all goods whose qualities vary are sold by auction．Among these are coffee，hi-der，skins，wool，tea，cocoa，furs，spices，fruit and vegetables and wines．Auction sales are alsousual for land and property，antique，furniture，pictures，rare books，old china，and similar works of art．The auction-rooms at Christie’s and Sotheby’S in London and New York are world famous． （）Auctioned goods are sold_________．

A.at a price less than their true value

B.very cheaply

C.for the highest price offered

D.only at fixed prices