当前位置:考试网  > 试卷库  > 技能鉴定  > 其他类  > 冶金工业技能鉴定  > 镀锡工  >  锡铁合金层不能超过一定的厚度,在一般情况下,厚度应该控制在0.4 ~0.8克/米2范围内。
试题预览

锡铁合金层不能超过一定的厚度,在一般情况下,厚度应该控制在0.4 ~0.8克/米2范围内。

1、正确
2、错误
查看答案
收藏
纠错
正确答案:

正确

答案解析:

暂无解析

你可能感兴趣的试题

WhichofthefollowingitalicizedwordsDOESNOTcarrythemetaphoricalmeaning?

Theonlysoundsarebirdcallsandthesoftnoise________________(当水缓缓推动草时草所发出的)

Theauthortellsusinparagraph4________.

Recentresearchhasclaimedthatanexcessofpositiveionsintheaircanhaveanilleffectonpeople’sphysicalorpsychologicalhealth.Whatarepositiveions?Well,theairisfullofions,electricallychargedparticles,andgenerallythereisaroughbalancebetweenthepositiveandthenegativecharged.Butsometimesthisbalancebecomesdisturbedandalargerproportionofpositiveionsarefound.Thishappensnaturallybeforethunderstorm,earthquakeswhenwindssuchastheMistral,HamsinorSharavareblowingincertaincountries.Oritcanbecausedbyabuild-upofstaticelectricityindoorsfromcarpetsorclothingmadeofman-madefibres,orfromTVsets,duplicatorsorcomputerdisplayscreens.

Whenalargenumberofpositiveionsarepresentintheairmanypeopleexperienceunpleasanteffectssuchasheadaches,fatigue,irritability,andsomesensitivepeoplesuffernauseaorevenmentaldisturbance.Animalsarealsoaffected,particularlybeforeearthquakes,snakeshavebeenobservedtocomeoutofhibernation,ratstofleefromtheirburrows,dogshowlandcatsjumpaboutunaccountably.ThishasledtheUSGeographicalSurveytofundanetworkofvolunteerstowatchanimalsinanefforttoforeseesuchdisastersbeforetheyhitvulnerableareassuchasCalifornia.

Conversely,whenlargenumbersofnegativeionsarepresent,thenpeoplehaveafeelingofwell-being.Naturalconditionsthatproducetheselargeamountsarenearthesea,closetowaterfallsorfountains,orinanyplacewherewaterissprayed,orformsaspray.Thisprobablyaccountsforthebeneficialeffectofaholidaybythesea,orinthemountainswithtumblingstreamsorwaterfalls.

Toincreasethesupplyofnegativeionsindoors,somescientistsrecommendtheuseofionisers:smallportablemachines,whichgeneratenegativeions.Theyclaimthationisersnotonlycleanandrefreshtheairbutalsoimprovethehealthofpeoplesensitivetoexcesspositiveions.Ofcourse,therearethedetractors,otherscientists,whodismisssuchclaimsandareskepticalaboutnegative/positiveionresearch.Thereforepeoplecanonlymakeuptheirownmindsbyobservingtheeffectsonthemselves,oronothers,ofanegativerichorpoorenvironment.Afterallitisdebatablewhetherdependingonseismicreadingstoanticipateearthquakesismoreeffectivethanwatchingthecat.

1.Whateffectdoesexceedingpositiveionizationhaveonsomepeople?

A.Theythinktheyareinsane.

B.Theyfeelratherbad-temperedandshort-fussed.

C.Theybecomeviolentlysick.

D.Theyaretootiredtodoanything.

2.Inaccordancewiththepassage,staticelectricitycanbecausedby___.

A.usinghome-madeelectricalgoods.

B.wearingclothesmadeofnaturalmaterials.

C.walkingonartificialfloorcoverings.

D.copyingTVprogramsonacomputer.

3.Ahighnegativeioncountislikelytobefound___.

A.nearapoundwithawaterpump.

B.closetoaslow-flowingriver.

C.highinsomebarrenmountains.

D.byarotatingwatersprinkler.

4.Whatkindofmachinecangeneratenegativeionsindoors?

A.Ionisers.

B.Air-conditioners.

C.Exhaust-fans

D.Vacuumpumps.

5.Somescientistsbelievethat___.

A.watchinganimalstoanticipateearthquakesismoreeffectivethandependingonseismography.

B.theunusualbehaviorofanimalscannotbetrusted.

C.neitherwatchingnorusingseismographsisreliable.

D.earthquake

Thecountry’schiefexportsarecoal,carsandcottongoods,cars_____themostimportantofthese.

热门试题 更多>
试题分类: 铁路车号员(长)
练习次数:0次
试题分类: 铁路道口工
练习次数:0次
试题分类: 铁路信号工
练习次数:0次
试题分类: 钢轨探伤工
练习次数:0次
试题分类: 计算机维修工
练习次数:1次
扫一扫,手机做题