Do you know who invented the slide – fastener, or rather, the zipper （拉链）? No one thought of anything like the zipper until Whitcomb Judson came along. Judson’s slide-fastener was an out-of-blue invention. No one knows what gave him the idea．No one even knows much about him, except that he was a mechanical engineer living in Chicago and that he patented other inventions to do with a street railway system and motorcars.
Judson invented the first zipper in 1891. This ingenious little device looks very simple, and the principle behind it is simple, too; yet it took a lot of years, together with another inventor to make the zipper really practical.
The zipper had to be produced cheaply, because no one would pay a lot of money for it．Judson invented a machine to mass-produce his slide-fastener．But the machine was terribly complicated and kept on breaking down. So in 1905 Judson invented a new fastener, the C-curity, which was easier to manufacture. Clothing manufacturers, however, were not the least bit interested in trying out the fasteners, so the only way Judson could get them on to the market was by letting pedlars（小贩）sell them from door to door．Moreover, the C-curity fastener was clumsy and had a bad habit of bursting open at inconvenient times.
Then a young Swedish engineer called Sundback came to work for Judson’s struggling company. He thought hard and decided that the interlocking parts needed to be much smaller to give the fastener greater flexibility and to stop it bursting open．After several attempts, Sundback invented a really practical fastener in 1913. It is in all important ways the same as the one we use today.
Clothing manufacturers still refused to use the fastener. But in 1918 an inventor showed the American army a flying suit he had invented．It happened to use the slide-fastener．The army put the suit through such tough tests that it disintegrated（分裂）---all except the fastener! A Navy officer happened to see the tests, and Judson’s unknown little company got an order for ten thousand fasteners．Later, Judson’s invention was used in the manufacture of rubber galoshes（橡胶套鞋） by a big company. They called the galoshes `Zippers´. This is how the slide-fastener got it s popular name.
1．What does the sentence “Whitcomb Judson’s slide-fastener was an out-of-blue invention” in the first paragraph mean?
A．That it was blue in color. B．That it was totally unexpected.
C．That it was excellent in quality. D．That it was not practical.
2．How many years did it take for a really practical zipper to be invented?
A．22 B．18 C．19 D．13
3．What do we know about Whitcomb Judson according to the passage?
A．It took Judson a lot of years to invent the first zippers.
B．Judson, together with Sundback invented a really practical fastener in 1913.
C．Judson invented a lot of things, not only including zippers but also a street railway system and motorcars.
D．People know little about Whitcomb Judson except a few facts.
4．What is the writer’s purpose of writing the passage?
A．To tell us how the zipper works.
B．To give a brief introduction about the inventors of the zipper.
C．To give us information about the invention of the zipper.
D．To argue who the real inventor of the zipper was.