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¡¡¡¡The most valuable rubbish in the world is not in the world, but in orbit around it£® Space has always contained "trash": a little dust raised from Earth by air currents, cosmic ray fragments, and some cosmic dust caused by meteors£® Explosions from the sun's surface may have added some atomic nuclei, carried outward into space by the solar wind£® But there is much more trash now£® When the hatch of a space capsule opens, dust particles float out£® Sometimes small objects escape£® Astronaut Edward White's heat-reflecting glove, dropped during the first space walk, is up there£® There are several thousand fragments from upper rocket stages, some satellites that did not work, and some satellites still working£® A Titan rocket that destroyed itself added 339 pieces to the orbiting rubbish£®
¡¡¡¡Several hundred man-made objects that were space travelers have disappeared: they burned up as they reentered Earth's atmosphere£® One famous piece that returned successfully was found in the United States, when two policemen kicked it out of the middle of a street in Wisconsin£® It was a twenty-pound piece of Russia's Sputnik IV£®
1£®Present-day space trash is called valuable because of_______£®
A£®materials used in it¡¡¡¡B£® the total cost of producing it
C£®its possible use as atomic energy D£®None of the above
2£®Before our time, Earth's only addition to space rubbish was_______£®
A£®some atomic nuclei¡¡¡¡B£® cosmic ray fragments
C£®cosmic dustD£® None of the above
3£® The writer says a space capsule adds to rubbish when________£®
A£®a hatch opens¡¡¡¡ B£®rockets fire
C£®food is jettisoned D£®any astronaut goes for a walk
4£®The article dropped during the first space walk was a_________£®
A£® camera B£® piece of nylon cord
C£®heat-reflecting glove D£® glare-proof plastic visor
5£®When a Titan rocket destroyed itself, the trash was increased by_____£®
A£®339 pieces B£®399 pieces
C£®several thousand pieces D£®twenty pounds
6£®Implied but not stated:
A£®Some working satellites are still in orbit£®
B£®There is some way of counting objects in orbit£®
C£®All objects that have disappeared from orbit have burned up on reentering our atmosphere£®
D£®Radar is used to track objects in space£®
7£®The policemen probably kicked the object they found because it_______£®
A£®was useless B£® had come from space
C£®might cause an accident D£® looked dangerous
8£®This famous object was from_______£®
A£®a Titan rocket¡¡¡¡ B£® an American lunar capsule
C£®Russia's Sputnik II D£® Russia's Sputnik IV
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