摘要
You,like all members of human communities,play several roles.At school you are a student,after school you may be on a sports team,at home you are part of a family.Organisms in a natural community also play different roles within their ecosystem.An organism’s role within an ecosystem depends on how it obtains its food.Plants and animals obtain their food in very different ways,so they have very different roles in an ecosystem.The way in which an organism obtains food also affects its interactions with other organisms in the ecosystem.
