C
Centuries ago, man discovered that removing moisture（湿气） from food helps to store it, and that the easiest way to do this is to expose the food to sun and wind.
All foods including water — cabbage and other leaf vegetables contains as much as 93% water, potatoes and other root vegetables 80%, lean (瘦的) meat 75% and fish, anything from 80% to 60%, depending on how fatty it is. If this water is removed, the activity of the bacteria which cause food to go bad is controlled.
Nowadays most foods are dried mechanically. The conventional method of such dehydration (脱水) is to put food in chambers (室) through which hot air is blown at temperature of about ll0'C at entry to about 43'C at exit. This is the usual method for drying such things as vegetables, minced meat, and fish.
Liquids such as milk, coffee, tea, soups and eggs may be dried by pouring them over a heated steel cylinder (圆筒), then put them into a chamber through which a current of hot air passes. In the first process, the dried material comes off the roller (滚筒) as a thin film which is then broken up into small, though still relatively flakes (薄片). In the second process it falls to the bottom of the chamber as small powder. Where recognizable pieces of meat and vegetables are required, as in soup, the ingredients (成分) are dried separately and then mixed.
Dried foods take up less room and weigh less than the same food packed in cans orfrozen, and they do not need to be stored in special conditions. For these reasons theyare invaluable to the climbers, explorers and soldiers in battle, who have little storagespace. They are also popular with housewives because it takes so little time to cook them.
54．It can be inferred from the passage that ________.
A．the fattier fish contain as much water as the lean one
B．the fattier the fish is, the more water it may contain
C．a fatty fish holds less water than a lean one
D．the water content of fish has nothing to do with the content of their fat
55．The underlined word "conventional" in Paragraph 3 can most probably be replaced by ______.
A．traditional       B．scientific       C.particular         D.special
56．Which of the following statements is NOT true about drying food?     
A．The removal of water in food helps prevent it from going rotten.
B．The open-air method of drying food has been known for hundreds of years.
C．In the course of dehydration, the temperature of hot current coming from entry to exit is
gradually going up.
D．The process of drying liquids is much more complex than that of drying solid food.
57．The last paragraph mainly talks about __________.
A．the reason why housewives like dried food
B．the general convenience of dried food
C．the methods of storing food
D．the advantages of dried, canned and frozen food