41.Thisisan_______thatwillnotbeeasilyforgotten.
42.Please_______meformyrudeness.Ireallydonotknowthecustomhere.
43.Waterandairare_______tohumanbeings.Wecannotlivewithoutthem.
44.Whentheairplanetakesoff,thepassengersaretoldto_______theirseatbelts.
45.Thisisnotwhatweaskedyoutodo.Youcannotgetmorepayforthe_______work.
46.Mythroatis_______.Icannotspeakanymore.
47.Manyyearsago,alotoffactorieswere_______frombigcitiestothemountainousareasincaseofwar.
48.Hesaidinhisletterthathewould_______somephotographsbutIcouldn’tfindanythingintheenvelope.
49.ManyEnglishwordsare_______fromLatin.
50.Ifeel_______tosaythatIcannotbelievewhathesaid.