时间:2016-03-30 07:24:47
选项】
A.Right
B.Wrong
C.Not mentioned
答案】A
解析】
21.题干】Brunel became an apprentice with his father when he was veryyoung.
选项】
A.Right
B.Wrong
C.Not mentioned
答案】A
解析】
22.题干】The Thames Tunnel project was more difficult than any previousprojects undertaken in Britain.
选项】
A.Right
B.Wrong
C.Not mentioned
答案】C
解析】
概括大意与完成句子
Geothermal(地热)Energy
1.Since heat naturally moves from hotter regions to cooler ones, the heatfrom the earth's center flows outwards towards the surface. In this way, ittransfers to the next layer of rock. If the temperature is high enough, some ofthis rock melts and forms magma(岩浆). The magma ascends in its turn towards theearth's surface. It often remains well below the earth's surface, creating vastareas of hot rock. In such regions, there are deep cracks, which allow rainwaterto descend underground. Some of the heated rainwater travels back up to theearth's surface where it will appear as a hot spring. However, if this ascendinghot water reaches a layer of impermeable(不可渗透的)rock, it remains trapped, forminga geothermal reservoir. If geothermal reservoirs are close enough to thesurface, they can be reached by drilling wells. Hot water and steam shoot up thewells naturally, and can be used to produce electricity in geothermal powerplants.
2.A few geothermal power plants depend on dry-stem reservoirs which producesteam but little or no water. In these cases, the steam is piped up directly toprovide the power to spin a turbine generator. The first geothermal power plant,constructed at Lardarello in Italy, was of this type, and is still producingelectricity today.
3.Most currently operating geothermal power plants are either "flash" steamplants or binary(双重的)plants. Flash plants produce mainly hot water ranging intemperature from 300° to 700°Fahrenheit. This water is passed through one or twoseparators where released from the pressure of the underground reservoir, it"flashes" or boils into steam Again, the force of this steam provides the energyto spin the turbine and produce electricity. The geothermal water and steam arethen reinjected directly back down into the earth to maintain the volume andpressure of the reservoir. Gradually they will be reheated and can then be usedagain.
4.A reservoir with temperatures below 300° Fahrenheit is not hot enough toflash steam but it can still be used to generate electricity in binary fluid.The steam from this is used to power the turbines. As in the flash steam plant,the geothermal water is recycled back into the reservoir.
23.题干】Paragraph1_____
选项】
A.Dry steam plants
B.Binary plants
C.Origin of geothermal energy
D.Generation of electricity
E.Flash steam plants
F.Recyclable water and steam
答案】C
解析】
24题干】Paragraph2_____
选项】
A.Dry steam plants
B.Binary plants
C.Origin of geothermal energy
D.Generation of electricity
E.Flash steam plants
F.Recyclable water and steam
答案】A
解析】
25题干】Paragraph3_____
选项】
A.Dry steam plants
B.Binary plants
C.Origin of geothermal energy
D.Generation of electricity
E.Flash steam plants
F.Recyclable water and steam
答案】E
解析】
26题干】Paragraph4_____
选项】
A.Dry steam plants
B.Binary plants
C.Origin of geothermal energy
D.Generation of electricity
E.Flash steam plants
F.Recyclable water and steam
答案】F
解析】
27.题干】A geothermal reservoir is formed when hot water is trapped under_____.
选项】
A.the energy to turn a turbine
B.impermeable rock
C.one or two separators
D.turbine operator
E.little or no water
F.hot springs
答案】B
解析】
28.题干】A dry-steam reservoir produces steam with _____.
选项】
A.the energy to turn a turbine
B.impermeable rock
C.one or two separators
D.turbine operator
E.little or no water
F.hot springs
答案】E
解析】
29.题干】Flash plants produce hot water through _____.
选项】
A.the energy to turn a turbine
B.impermeable rock
C.one or two separators
D.turbine operator
E.little or no water
F.hot springs
答案】C
解析】
30.题干】In a binary plant, the heat of the geothermal water can be convertedinto _____.
选项】
A.the energy to turn a turbine
B.impermeable rock
C.one or two separators
D.turbine operator
E.little or no water
F.hot springs
答案】A
解析】
阅读理解
第一篇
Black Holes Trigger Stars to Self-Destruct
Scientists have long understood that supermassive black holes weighingmillions or billions of suns can tear apart stars that come too close. The blackhotels gravity pulls harder on the nearest part of the star, an imbalance thatpulls the star apart over a period of minutes or hours, once it gets closeenough.
Scientists say this Uneven pulling is not the only hazard facing the star.The strain of these unbalanced forces can also trigger a nuclear explosionpowerful enough to destroy the star from within. Matthieu Brassart andJean-Pierre Luminet of the Observatoire de Paris in Meudon, France, carried outcomputer simulations of the final moments of such an unfortunate star's life，asit veered towards a supermassive black hole.
When the star gets close enough, the uneven forces flatten it into a pancakeshape. Some previous studies had suggested this flattening would increase thedensity and temperature inside the star enough to trigger intense nuclearreactions that would tear it apart. But other studies had suggested that thepicture would be complicated by shock waves generated during the flatteningprocess and that no nuclear explosion should occur.
The new simulations investigated the effects of shock waves in detail，andfound that even when their effects are included，the conditions favor a nuclearexplosion. "There will be an explosion of the star-it will be completelydestroyed," Brassart says. Although the explosion obli