Thefloordoesnotlooksobadwhen________(sweep)clean.
Ihavebeenstudyinghereforfouryears,bynextsummerI________.
Ifound________toanswerallthequestionswithinthetimegiven.
Ipreferthisdiagram________thatone.
heteachertoldthemsincelight________(travel)fasterthansound,lightning________(appear)togobeforethunder.