Arrivingatthebusstop,_____waitingthere.
Henoticedthehelicopterhoveringoverthefield.Thentohisastonishment,hesawaropeladder_____outandthreemenclimbingdownit.
____,sheledalifeofcompleteseclusion.
Ineverregretted_____hisoffer,foritwasnotwheremyinterestlay.
Ifasubstanceisdissolvedinwaterorheated，itmay（）agas.
