Theauthortellsusinparagraph4________.
一产妇临产8小时，肛查头先露，宫口已开全，先露+4，请问此时产力组成是下列哪种情况
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.