无剩余压力的气瓶,充装前应充入氮气置换后抽真空。
1、正确正确
暂无解析
Thespeed____Tomdriveshiscaristoohigh.
Hehadalongtelephone( ).
MRKConsultingLtdhasbeenoperatingintheglobalmarketsince1988.WehavesuccessfullyplacedhundredsofIT&BankingprofessionalsinleadingcompaniesintheFinance,BankingandITindustries.
Thebike____hewenttoschoolwasstolenlastweek,whichmadehimfeelsad.
Nancy:MayIseeyourdrivinglicenseandvehicleregistrationcard,please?
Dick:______.