1___theremanytreesonthecampus?no,butnowwehavemanyeverythere.
a,wereb,hadc,didhave
2we__inthesea,thewaterwastoocold.
a,swamnotb,didn'tswimc,didn'tswam
3__theteacher__atthiscollegelastyear?yes,hedid.
a,didtaughtb,doesteachc,didteach
4Prof,Green__sickyesterday.he__afever.nowhestillsfeelweak.
a,ishasb,washavec,washad