1997年8月托福考试阅读理解全真试题

　　Barbed wire， first patented in the United States in 1867，played an important part in the development of American farming， as it enabled the settlers to make effective fencing to enclose their land and keep cattle away from their crops. This had a considerable effect on cattle ranching， since the herds no longer had unrestricted use of the plans for grazing， and the fencing led to conflict between the farmers and the cattle ranchers.

　　Before barbed wire came into general use， fencing was often made from serrated wire， which was unsatisfactory because it broke easily when under strain， and could snap in cold weather due to contraction. The first practical machine for producing barbed wire was invented in 1874 by an Illinois farmer， and between then and the end of the century about 400 types of barbed wire were devised， of which only about a dozen were ever put to practical use.

　　Modern barbed wire is made from mild steel high-tensile steel， or aluminum. Mild steel and aluminum barbed wire have two strands twisted together to form a cable which is stronger than single-strand wire and less affected by temperature changes. Single-strand wire， round or oval， is made from high-tensile steel with the barbs crimped or welded on . The steel wires used are galvanized - coated with zinc to make them rustproof. The two wires that make up the line wire or cable are fed separately into a machine at one end. They leave it at the other end twisted-together and barbed. The wire to make the barbs is fed into the machine from the sides and cut to length by knives that cut diagonally through the wire to produce a sharp point. This process continues automatically，and the finished barbed wire is wound onto reels， usually made of wire in length of 400 meters or in weights of up to 50 kilograms.

　　A variation of barbed wire is also used for military purposes. It is formed into long coils or entanglements called concertina wire.

　　11.What is the main topic of the passage？

　　（A） Cattle ranching in the United States.

　　（B） A type of fencing

　　（C） Industrial uses of wire

　　（D） A controversy over land use.

　　12.The word "unrestricted" in line 5 is closest in meaning to

　　（A） unsatisfactory

　　（B） difficult

　　（C） considerable

　　（D） unlimited

　　13.The word "snap" in line 10 could best be replaced by which of the following？

　　（A） freeze

　　（B） click

　　（C） loosen

　　（D） break

　　14.What is the benefit of using two-stranded barbed wire？

　　（A） Improved rust-resistance

　　（B） Increased strength

　　（C） More rapid attachment of barbs

　　（D） Easier installation.

　　15.According to the author， the steel wires used to make barbed wire are specially processed to

　　（A） protect them against rust

　　（B） make them more flexible

　　（C） prevent contraction in cold weather

　　（D） straighten them.

　　16.The word "fed" in line 24 is closest in meaning to

　　（A） put

　　（B） eaten

　　（C） bitten

　　（D） nourished

　　17.The knives referred to in line 27 are used to

　　（A） separate double-stranded wire

　　（B） prevent the reel from advancing too rapidly

　　（C） twist the wire

　　（D） cut the wire that becomes barbs

　　18.What is the author s purpose in the third paragraph？

　　（A） To explain the importance of the wire.

　　（B） To outline the difficulty of making the wire

　　（C） To describe how the wire is made

　　（D） To suggest several different uses of the wire.

　　19.According to the passage， concertina wire is used for

　　（A） livestock management

　　（B） international communications

　　（C） prison enclosures

　　（D） military purposes.

　　20.Which of the following most closely resembles the fencing described in the passage？

　　（A） （图）

　　（B） （图）

　　（C） （图）

　　（D） （图）