sentences: a producer produces its own food & plants are a kind of producer ->  a plant can produce its own food  an animal is a kind of consumer & a consumer can not produce its own food ->  an animal can not produce its own food  a plant can produce its own food & an animal can not produce its own food ->  a plant can produce its own food but an animal can not produce its own food  a plant can produce its own food but an animal can not produce its own food & if one thing can do something but another thing can not do that something then those two things are different -> plants and animals are different because a plant can produce its own food but an animal can not produce its own food