Wire的意思是()。
A:线框 B:双面 C:面贴图 D:细化面
线框(Wire frame)
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 the cattle ranching, since the herds no longer had unrestricted use of the plains 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(边沿呈锯齿型的) 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 the 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, round or oval, is made from high-tensile steel with the barbs crimped(使弯曲) or welded on. The steel wires used are galvanized—coated with zinc(锌) to make them rustproof. The two wires that make up the line wire or cable are fed separately into a machine at one en& 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(对角线)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 lengths of 400 meters or in weights of up to 50 kilograms.
The author's purpose of writing the third paragraph is ()
A:to suggest several different use of the wire B:to explain the importance of wire C:to describe how the wire is made D:to outline the difficulty of making the wire
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 the cattle ranching, since the herds no longer had unrestricted use of the plains 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(边沿呈锯齿型的) 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 the 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, round or oval, is made from high-tensile steel with the barbs crimped(使弯曲) or welded on. The steel wires used are galvanized—coated with zinc(锌) to make them rustproof. The two wires that make up the line wire or cable are fed separately into a machine at one en& 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(对角线)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 lengths of 400 meters or in weights of up to 50 kilograms.
The underlined word "knives" is used to()
A:prevent the reel from advancing to rapidly B:twist the wire C:separate doublestranded wire D:cut the wire that becomes barbs
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 the cattle ranching, since the herds no longer had unrestricted use of the plains 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(边沿呈锯齿型的) 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 the 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, round or oval, is made from high-tensile steel with the barbs crimped(使弯曲) or welded on. The steel wires used are galvanized—coated with zinc(锌) to make them rustproof. The two wires that make up the line wire or cable are fed separately into a machine at one en& 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(对角线)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 lengths of 400 meters or in weights of up to 50 kilograms.
What is the main topic of the passage()
A:A new type of fencing is introduced. B:Cattle ranching and farming in the United States. C:Barbed wire is better than singlestranded wire. D:How the wires were made in industry.
What is the benefit of using two stranded barbed wire
A:Easier installation. B:Improved rust-resistance. C:Increased strength. D:More rapid attachment of barbs.
According to the author, the steel wires used to make barbed wire are specially processed to ______.
A:make them more flexible B:protect them against rust C:straighten them D:prevent contraction in cold weather