Passage Two
Centuries ago,man discovered that removing moisture from food helps to preserve it,and that the easiest way to do this is to (71) the food to the sun and wind.
All foods contain water — cabbage and other leaf vegetables contain as (72) as 93% water,potatoes and other root vegetables 80%,lean meat 75% and fish anything from 60% to 80% depending on (73) fatty it is.If this water is removed,the activity of the bacteria which cause food to go (74) is checked.
Nowadays most foods are dried mechanically.The traditional method of such dehydration is to put food in chambers through which hot air is blown at temperatures of about 110℃ at entrance to about 43℃ at exit.This is the usual method for drying such things as vegetables,minced meat,and fish.
Dried foods take (75) less room and weigh less than the same food packed in cans or frozen,and they do not need to be (76) in special conditions.(77) these reasons they are (78) to climbers,explorers and soldiers in battle who have little storage space.They are also popular (79) housewives because it takes so little time to cook them.Usually it is just a case of (80) the dried-out moisture with boiling water.
71.A.put B.expose
C.take D.get
72.A.many B.great
C.much D.more
73.A.what B.where
C.which D.how
74.A.wrong B.incorrect
C.bad D.false
75.A.out B.up
C.over D.on
76.A.stressed B.strapped
C.stored D.subjected
77.A.With B.For
C.By D.In
78.A.available B.valueless
C.worthless D.invaluable
79.A.for B.in
C.with D.to
80.A.restoring B.replacing
C.renewing D.relieving