1)b.not...until...直到...才...
2)a as soon as...一...就...
3)c.hardly...when...一...就.=no sooner...than...(一般用过去完成时,且no sooner放句首还要部分倒装)
4)c.自从过去的某个时间开始____thefightstopped,travelacrossthecountryhas beenquitesafeasincebbefore cwhered unlesstheywerejust readyto leave ___the telephoneranga before bwhen csinced thoughwe hadn'tquite reachedtheoffice ___the carbroke downa thanb ifc when d asa 既然,因为;b这时候(发生另外一件事);c(同上题)theywerejust readyto leave ___the telephoneranga before bwhen csinced thoughwe hadn'tquite reachedtheoffice ___the carbroke downa thanb ifc when d asb,cbe going to do sth when...be doing sth whenbe about to do sth whenbe to do sth whenhardly...when(hardly表示否定,同理had not done sth when...快要...这时...)......