Onlywhenyouhaveobtainedsufficientdata________cometoasoundconclusion.
A、canyouYou________gonow.It’sgettinglate.
heteachertoldthemsincelight________(travel)fasterthansound,lightning________(appear)togobeforethunder.
Thosewho’dliketovisittheexhibition________(sign)yournameshere.
Ifound________toanswerallthequestionswithinthetimegiven.
Thefloordoesnotlooksobadwhen________(sweep)clean.