题目内容
Plastic is the panacea of the ages. Nearly every man-made object (1)_____ (2)_____ of, or at least (3)_____ its very structure, to this wonder compound. Rain slickers, computer terminals, automobile engine parts, coffee cups (and the sugar stirrers too), breast implants, toy soldiers—they are all made up of plastic, or one of its many (4)_____ Since the (5)_____ of civilization, humankind bas been experimenting (6)_____ a multifunctional material—one that had to be equally strong and lightweight—to carry, contain and protect valuables. (7)_____ it could carry, contain and protect humans too, even better. Generations of tinkerers and scientists set off (8)_____ the challenge, striking gold some 170 years ago. By mixing natural rubber with sulphur they created the world"s most utilized material ever. In developing a (9)_____, malleable and durable substance, the most important inventions of the industrial age were to follow shortly thereafter. The automobile and airplane industries, to (10)_____ just two, owe their very existence to plastic. And, (11)_____ celluloid plastic strips, the Lumiere Brothers would never have brought moving pictures to the big screen. The development of plastic is a story of human (12)_____, ingenuity and luck. (13)_____ the legend now goes, in 1839, the American inventor Charles Goodyear (the famous tyre company would later use his name) was experimenting with the sulphur treatment of natural rubber when he dropped a piece of sulphur-treated rubber on a stove. The heat seemed to give rubber (14)_____ properties. It was stronger, more (15)_____ to abrasions more elastic, much less (16)_____ to temperature, (17)_____ to gases, and highly resistant to chemicals and electric (18)_____ Eyeing this as a cheaply and easily reproduced construction material, a whirlwind of work (19)_____ and the birth of (20)_____ plastic and plastic-derivatives were born from camphor to celluloid to rayon; cellophane, polyvinyl chloride (or PVC); styrofoam and nylon were soon to follow.
查看答案
搜索结果不匹配？点我反馈
更多问题
Plastic is the panacea of the ages. Nearly every man-made object (1)_____ (2)_____ of, or at least (3)_____ its very structure, to this wonder compound. Rain slickers, computer terminals, automobile engine parts, coffee cups (and the sugar stirrers too), breast implants, toy soldiers—they are all made up of plastic, or one of its many (4)_____ Since the (5)_____ of civilization, humankind bas been experimenting (6)_____ a multifunctional material—one that had to be equally strong and lightweight—to carry, contain and protect valuables. (7)_____ it could carry, contain and protect humans too, even better. Generations of tinkerers and scientists set off (8)_____ the challenge, striking gold some 170 years ago. By mixing natural rubber with sulphur they created the world"s most utilized material ever. In developing a (9)_____, malleable and durable substance, the most important inventions of the industrial age were to follow shortly thereafter. The automobile and airplane industries, to (10)_____ just two, owe their very existence to plastic. And, (11)_____ celluloid plastic strips, the Lumiere Brothers would never have brought moving pictures to the big screen. The development of plastic is a story of human (12)_____, ingenuity and luck. (13)_____ the legend now goes, in 1839, the American inventor Charles Goodyear (the famous tyre company would later use his name) was experimenting with the sulphur treatment of natural rubber when he dropped a piece of sulphur-treated rubber on a stove. The heat seemed to give rubber (14)_____ properties. It was stronger, more (15)_____ to abrasions more elastic, much less (16)_____ to temperature, (17)_____ to gases, and highly resistant to chemicals and electric (18)_____ Eyeing this as a cheaply and easily reproduced construction material, a whirlwind of work (19)_____ and the birth of (20)_____ plastic and plastic-derivatives were born from camphor to celluloid to rayon; cellophane, polyvinyl chloride (or PVC); styrofoam and nylon were soon to follow.
Plastic is the panacea of the ages. Nearly every man-made object (1)_____ (2)_____ of, or at least (3)_____ its very structure, to this wonder compound. Rain slickers, computer terminals, automobile engine parts, coffee cups (and the sugar stirrers too), breast implants, toy soldiers—they are all made up of plastic, or one of its many (4)_____ Since the (5)_____ of civilization, humankind bas been experimenting (6)_____ a multifunctional material—one that had to be equally strong and lightweight—to carry, contain and protect valuables. (7)_____ it could carry, contain and protect humans too, even better. Generations of tinkerers and scientists set off (8)_____ the challenge, striking gold some 170 years ago. By mixing natural rubber with sulphur they created the world"s most utilized material ever. In developing a (9)_____, malleable and durable substance, the most important inventions of the industrial age were to follow shortly thereafter. The automobile and airplane industries, to (10)_____ just two, owe their very existence to plastic. And, (11)_____ celluloid plastic strips, the Lumiere Brothers would never have brought moving pictures to the big screen. The development of plastic is a story of human (12)_____, ingenuity and luck. (13)_____ the legend now goes, in 1839, the American inventor Charles Goodyear (the famous tyre company would later use his name) was experimenting with the sulphur treatment of natural rubber when he dropped a piece of sulphur-treated rubber on a stove. The heat seemed to give rubber (14)_____ properties. It was stronger, more (15)_____ to abrasions more elastic, much less (16)_____ to temperature, (17)_____ to gases, and highly resistant to chemicals and electric (18)_____ Eyeing this as a cheaply and easily reproduced construction material, a whirlwind of work (19)_____ and the birth of (20)_____ plastic and plastic-derivatives were born from camphor to celluloid to rayon; cellophane, polyvinyl chloride (or PVC); styrofoam and nylon were soon to follow.
Plastic is the panacea of the ages. Nearly every man-made object (1)_____ (2)_____ of, or at least (3)_____ its very structure, to this wonder compound. Rain slickers, computer terminals, automobile engine parts, coffee cups (and the sugar stirrers too), breast implants, toy soldiers—they are all made up of plastic, or one of its many (4)_____ Since the (5)_____ of civilization, humankind bas been experimenting (6)_____ a multifunctional material—one that had to be equally strong and lightweight—to carry, contain and protect valuables. (7)_____ it could carry, contain and protect humans too, even better. Generations of tinkerers and scientists set off (8)_____ the challenge, striking gold some 170 years ago. By mixing natural rubber with sulphur they created the world"s most utilized material ever. In developing a (9)_____, malleable and durable substance, the most important inventions of the industrial age were to follow shortly thereafter. The automobile and airplane industries, to (10)_____ just two, owe their very existence to plastic. And, (11)_____ celluloid plastic strips, the Lumiere Brothers would never have brought moving pictures to the big screen. The development of plastic is a story of human (12)_____, ingenuity and luck. (13)_____ the legend now goes, in 1839, the American inventor Charles Goodyear (the famous tyre company would later use his name) was experimenting with the sulphur treatment of natural rubber when he dropped a piece of sulphur-treated rubber on a stove. The heat seemed to give rubber (14)_____ properties. It was stronger, more (15)_____ to abrasions more elastic, much less (16)_____ to temperature, (17)_____ to gases, and highly resistant to chemicals and electric (18)_____ Eyeing this as a cheaply and easily reproduced construction material, a whirlwind of work (19)_____ and the birth of (20)_____ plastic and plastic-derivatives were born from camphor to celluloid to rayon; cellophane, polyvinyl chloride (or PVC); styrofoam and nylon were soon to follow.
You are going to read a list of headings and a text about the Deep Impact by NASA. Choose the most suitable heading from the list for each numbered paragraph.A. Revelation of the nature of cometsB. A perfect representative of the cometsC. Hoping for the bestD. Right time and right place for the ImpactE. What to expect of this Deep ImpactF. Mystery in the heavens On Monday at 1:52 a.m. ET, a probe deployed by a NASA spacecraft 83 million miles from home will smash at 23,000 mph into an ancient comet the size of Manhattan, blasting a hole perhaps 14 stories deep. (41)______. Launched in January, NASA"s $333 million Deep Impact mission is designed to answer questions that scientists have long had about comets, the ominous icebergs of space. This is the first time any space agency has staged such a deliberate crash. Scientists hope images transmitted by the probe and its mother ship will tell them about conditions in the early solar system, when comets and planets, including Earth, were formed. The team hopes to release photos of the impact as soon as they are received from the craft. NASA and observatories across the nation will be releasing webcasts. (42)______. At the very least, NASA says, knowing how deep the probe dives into the comet could settle the debate over whether comets are compact ice cubes or porous snow cones. "We need to dig as deep a hole as possible," says mission science Chief Michael A"Hearn of the University of Maryland. Until now, the closest scientists have come to a comet was when NASA"s Stardust mission passed within 167 miles of the comet Wild 2 last year, collecting comet dust that is bound for a return to Earth in January. The most famous date with a comet occurred when an international spacecraft flotilla greeted Halley"s Comet in 1986. But these quick looks examined only the comets" dust and surface. (43)______. To the ancients, comets were harbingers of doom, celestial intruders on the perfection of the heavens that presaged disaster. Modern astronomers have looked on them more favorably, at least since Edmond Halley"s celebrated 1705 prediction of the return of Halley"s Comet in 1758 and every 75 years thereafter. Today, scientists believe Tempel 1 (named for Ernst Wilhelm Leberecht Tempel, who first spotted it in 1867 while searching for comets in the sky over Marseilles, France) and other comets are windows to the earliest days of the solar system, 4.6 billion years ago, when planets formed from the dust disk surrounding the infant sum (44)______. Deep Impact"s copper-plated "impactor"—a 39-inch long, 820-pound beer-barrel-shaped probe—will be "run over like a penny on a train track" when it crashes, A"Hearn says. The impactor is equipped with a navigation system to make sure it smacks into the comet in the right location for the flyby craft"s cameras. On Sunday, the flyby spacecraft will release the probe. Twelve minutes later, it will beat a hasty retreat with a maneuver aimed at allowing a close flyby, from 5,348 miles away, with cameras pointed. Fourteen minutes after the impact, the flyby spacecraft will scoot to within a mere 310 miles for a close-up of the damage, (45)______. Ideally, everything will line up, and the flyby spacecraft will take images of the crater caused by the impact. It will go into a "shielded" mode as ice and dust batter the craft, then emerge to take more pictures. "The realistic worst case is hitting (the comet) but not having the flyby in the right place," A"Hearn says. "Basically, we have a bullet trying to hit a second bullet with a third bullet in the right place at the right time to watch, I"d love to have a joystick(操纵杆) to control the impactor." Planetary scientists have "no idea" what sort of crater will result, McFadden says. Predictions range from a deep but skinny shaft driven into a porous snow cone to a football- stadium-sized excavation in a hard-packed ice ball. But astronomers should have their answer shortly after impact, which should settle some questions about the comet"s crust and interior. Analysis of the chemistry of that interior, based on the light spectra given off in the impact"s aftermath, could take much longer.
微信支付 
支付宝支付