sentences: air is a kind of gas0 & something exchanging things with something else means that something taking one kind of thing from that something else and giving off another kind of thing to that something else ->  an example of an animal exchanging things with something else is that animal inhaling one kind of thing from that something else and giving off another kind of thing to that something else  an example of an animal exchanging things with something else is that animal inhaling one kind of thing from that something else and giving off another kind of thing to that something else & an example of giving something off is an animal exhaling ->  an example of an animal exchanging things with something else is that animal inhaling one kind of thing from that something else and exhaling another kind of thing to that something else  breathing in is when animals inhale air into their lungs & breathing out is when animals exhale / expel carbon dioxide from their lungs into the air ->  breathing is when animals inhale air and exhale carbon dioxide into the air  breathing is when animals inhale air and exhale carbon dioxide into the air & air is a part of the environment ->  breathing is when animals inhale air from the environment and exhale carbon dioxide into the environment  air is a kind of gas & carbon dioxide is a kind of gas ->  air and carbon dioxide are both kinds of gasses  breathing is when animals inhale air from the environment and exhale carbon dioxide into the environment & air and carbon dioxide are both kinds of gasses ->  breathing is when an animal inhales one kind of gas from the environment and exhales another kind of gas into the environment  an example of an animal exchanging things with something else is that animal inhaling one kind of thing from that something else and exhaling another kind of thing to that something else & breathing is when an animal inhales one kind of gas from the environment and exhales another kind of gas into the environment ->  an example of an animal exchanging gasses with the environment is an animal breathing  an example of an animal exchanging gasses with the environment is an animal breathing & a lung is a kind of organ for breathing air ->  a lung is a kind of organ for exchanging gasses with the environment  a lung is a kind of organ for exchanging gasses with the environment & the lungs are a part of the respiratory system -> the respiratory system is used for exchanging gasses with the environment