sentences: if something is left out in the open then that something is exposed to oxygen & a lit candle is left out in the open ->  the lit candle left out in the open is exposed to unlimited oxygen  the lit candle left out in the open is exposed to unlimited oxygen & as the amount of oxygen exposed to a fire increases the fire will burn longer & a lit candle is on fire ->  the candle that is left out in the open will keep burning  oxygen is a kind of matter0 & if something is covered in a close space, then it is exposed to limited oxygen ->  the lit candle covered in a large jar is exposed to a limited amount of oxygen  the lit candle covered in a large jar is exposed to a limited amount of oxygen & as the amount of oxygen exposed to a fire increases the fire will burn longer & a lit candle is on fire ->  the candle that is covered in a large jar will burn for a limited amount of time  if something is covered in a close space, then it is exposed to limited oxygen & a lit candle is covered in a small jar ->  the lit candle covered in a small jar is exposed to a limited amount of oxygen  the lit candle covered in a small jar is exposed to a limited amount of oxygen & as the amount of oxygen exposed to a fire increases the fire will burn longer & a lit candle is on fire ->  the candle that is covered in a small jar will burn for a limited amount of time  oxygen is a kind of matter & oxygen is a kind of matter1 ->  a vaccum has no oxygen in it  a vaccum has no oxygen in it & a fire requires oxygen to burn ->  a fire cannot burn in a vaccum  a fire cannot burn in a vaccum & the fourth lit candle is placed in a vaccum & a lit candle is on fire ->  the fourth candle will stop burning when it's placed in the vaccum  the candle that is left out in the open will keep burning & the candle that is covered in a large jar will burn for a limited amount of time & the candle that is covered in a small jar will burn for a limited amount of time & the fourth candle will stop burning when it's placed in the vaccum -> the candle left out in the open stay burning the longest