将军偏爱神医妻
例如高考题:
Annealing
将军偏爱神医妻
Annealingisawayofmakingmetalsofterbyheatingitandthenlettingitcoolveryslowly.Ifmetalisheatedandthencooledveryquickly,forexamplebydipping(浸)itinwater,itwillbeveryhardbutalsoverybrittle-thatis,itwillbreakeasily.Metalthathasbeenannealedissoftbutdoesnotbreakaseasily.Itispossibletomakemetalashardorassoftasitiswished,byannealingit.Themetalisheated,andallowedtocoolslowlyforacertainlengthoftime.Thelongertheheatedmetaltakestocoolslowly,thesofteritbecomes.Annealingcanalsobeusedonothermaterial,suchasglass.
将军偏爱神医妻
1.Whydopeopleputhotmetalinwater?
将军偏爱神医妻
A.Tomakeithard.B.Tomakeitsoft.
C.Tomakeitcool.D.Tomakeitbrittle.
2.Inannealing,therequiredhardnessofmetaldependson__.
A.thequantityofwaterusedB.thetemperatureofthemetal
C.thesoftnessofthemetalD.thetimingoftheoperation
3.Assuggestedbythetext,howcanglassbemadelessbrittle?
A.Itcanbeheatedandthencooledquickly.
B.Itcanbecooledandthenheatedslowly.
C.Itcanbeheatedandthencooledslowly.
D.Itcanbecooledandthenheatedquickly.
1、答案为A,此题属推断归纳题.文中第二句说如果把金属加热,然后迅速放到水里冷却,也就会变得非常硬,但也变得脆.hard是工艺的主观目的.brittle是伴随的客观结果,故选A而不选D.B项明显错误;C项是手段不是目的,因此,都可排除.
2、答案为D,此题属概括归纳题.timing是时间的选择.本答案的依据是5和6两句,"Themetalisheated,…lengthoftime.","Thelonger…thesofteritbecomes."cool的时间是可以控制的,时间越长越soft,即硬度就越低.由此我们可得出结论:在退火过程中,金属的硬度是受到冷却的时间长短影响的.