In order not to be disturbed, I spent three hours _______ in my study.
_____tohavelunchwithustoday?
Everyone_____dohisbesttomaketheworldsafeandclean.
Heaskedmeifhe_____openthewindow.
Sincetheroadiswetthismorning,_____lastnight.
IncaseI_____,Iwouldtryagain.