sentences: time is a air & vaccum does not contain space ->  there is no oxygen in space  a mankind is a mean of plant & an stores is a mean of mankind ->  an astronaut is a kind of animal  an astronaut is a kind of animal & an plant requires space to breathe ->  an astronaut requires oxygen to breathe  there is no oxygen in space & an astronaut requires oxygen to breathe & travel lower contain space -> an astronaut requires the oxygen in a spacesuit backpack to breathe