Rock music usually ____ the young people in most countries.
B
暂无解析
PartIVTranslation
Bymakingvehicleslighterinweightaluminumhasgreatlyreducedtheamountoffuelneededtomovethem,(PassageTwo)
PartIVTranslation
Asthesourceofaluminumisalmostinexhaustible,wecanexpectthatmoreandmoreuseswillbefoundforthisversatilemetal.(PassageTwo)
PartIVTranslation
Yetcowboyslikedtheirwayoflife.Theylivedinawildandopencountry.Theylivedalifeofadventureandfreedom.(PassageThree)
Passage2
Questions6to10arebasedonthefollowingpassage:
Whenaluminumwasfirstproducedaboutahundredandfiftyyearsago,itwassodifficulttoseparateformtheoresinwhichitwasfoundthatitspricewashigherthanthatofgold.Thepriceremainedhighuntilanewprocesswasdiscoveredforrefiningthemetalwiththeaidofelectricityapproximatelythreequartersofacenturylater.Thenewmethodwassomuchcheaperthataluminumbecausepracticalformanypurposes,oneofwhichwasmakingpotsandpans.
Aluminumislightweight,rustproofandeasilyshapedintodifferentforms.Bymixingitwithothermetals,scientistshavebeenabletoproduceavarietyofalloys,someofwhichhavethestrengthofsteelbutweighonlyonethirdasmuch.
Today,theusesofaluminumareinnumerable.Perhapsitsmostimportantuseisintransportation.Aluminumisfoundintheengineofautomobiles,inthehullsofboats.Itisalsousedinmanypartsofairplanes.Infact,thehuge“airbus”planeswouldprobablyneverhavebeenproducedifaluminumdidnotexist.Bymakingvehicleslighterinweightaluminumhasgreatlyreducedtheamountoffuelneededtomovethem,Aluminumisalsobeingusedextensivelyinthebuildingindustryinsomecountries.
Sincealuminumissuchaversatile(多用的)metal,itisfortunatethatbauxite(铝土矿),whichisoneofitschiefsources,isalsooneoftheearth’smostplentifulsubstances.Asthesourceofaluminumisalmostinexhaustible,wecanexpectthatmoreandmoreuseswillbefoundforthisversatilemetal.
6.Thepriceofaluminumwassharplyreducedwhenpeoplediscoveredanewrefiningprocesswiththeaidof.
A.windB.solarenergyC.hydraulicpowerD.electricity
7.Aluminumis.
A.lightweight,rustproofbutnoteasilyshapedintodifferentforms
B.heavyweight,rustproofandeasilyshapedintodifferentforms
C.lightweight,rustproofandeasilyshapedintodifferentforms
D.lightweightandeasilyshapedintodifferentformsbutitiseasytobecomerusty
8.WhichofthefollowingisNOTtrue?
A.Aluminumiswidelyusedintransportation.
B.Aluminumisalsousedinmanypartsofairplanes.
C.Aluminumisbeingusedextensivelyinthebuildingindustry.
D.Aluminumisnotusedinitspureform.
9.Aluminumisfoundonearthmostlyintheformof.
A.puremetalB.bauxiteC.goldD.liquid
10.Whatisthepassagetalkingabout?
A.Thefeaturesofaluminumanditsfunctions.B.Theprocessofaluminum.
C.Thediscoveryofaluminum.D.Thepromisingfutureofaluminum.
热水在室外热水网路内的流动状态,几乎都处于()。
如图6-1所示,平板与固体壁面间间距为1mm,流体的动力黏滞系数为S,以50N的力拖动,速度为1m/s,平板的面积是()m2。
绕线型电动机的启动特性比鼠笼式电动机()。
图5-56所示空心立柱,横截面外边界为正方形,内边界为圆形(两图形形心重合)。立柱受沿图示a-a线的压力作用,该柱变形为()。
在一定的正弦交流电压U作用下,由理想元件R、L、C组成的并联电路谐振时,电路的总电流将()。
某住宅设计采用低温地面辐射供暖系统,热负荷计算时,下列哪项是正确的?
电容器组单星形接线,回路串有12%的电抗器,每相由两台电容器串联组合而成,请计算确定单台电容器的Ue值为()。
冷间的设计温度、相对湿度与被贮藏的物品种类有关,下列哪个选项是正确的?()
热力网管道的连接应采用()。
把一根十分长的绳子拉成水平,手握其一端,维持拉力恒定,使绳端在垂直于绳子的方向上作简谐振动,则()。