heteachertoldthemsincelight________(travel)fasterthansound,lightning________(appear)togobeforethunder.
________(catch)intherain,hewaswettotheskin.
Ihavebeenstudyinghereforfouryears,bynextsummerI________.
Iwonderifhecouldgetit________(do)beforetomorrow.
Night________(fall),wehurriedhome.
________(fail)severaltimes,theyneedsomeencouragement.