机电专业英语第2版电子教案unit+4.doc

Unit4HeatTreatment&HotWorkingofMetalsⅠ.Lead-%%byweight,,butvariousotheralloyingelementsareused,suchasmanganese,chromium,vanadium,,(soluteelements,precipitatedphase)controlsqualitiessuchasthehardness,ductility,,,monaftermore--19thcentury,steelbecameaninexpensivemass-,suchasbasicoxygensteelmaking(BOS),,monmaterialsintheworld,,infrastructure,tools,ships,automobiles,machines,appliances,[m?'lekj?l?],分子的1)molecularstructure分子结构2)。3)。['lai?bl],有义务的,应受罚的,有…倾向的1)beliabletoseasickness容易晕船2)。3)。[skwi:z](压,干),压榨,***,紧握11)squeezeouttears挤出眼泪2)squeezethroughthecrowd挤入人群3)。['prai?],在前的,优先的1)agreewithoutpriorconsultation不谋而合2)。3)。[kr?k]v.&,裂纹,打开1)acrack一道缝儿2)crackabook打开书本阅读3)crackapersonoverthehead在某人头上重重一击4)There'sasinister-looki