if a thing uses something that comes from a source then that thing uses the source of that something0 & green plants are a kind of producer ->  food is a source of energy for producers  food is a source of energy for producers & one can get something from a source ->  producers can get energy from food  green plants provide food for themselves / animals / consumers by performing photosynthesis & making something is a kind of method for providing something ->  green plants make food by performing photosynthesis  photosynthesis is a kind of chemical process & if a living thing requires something for a process then that living thing uses that something for that process ->  if a living thing requires something for photosynthesis then that living thing uses that something for photosynthesis  if a living thing requires something for photosynthesis then that living thing uses that something for photosynthesis & a plant requires sunlight for photosynthesis & a plant is a kind of living thing ->  a plant uses sunlight for photosynthesis  a plant uses sunlight for photosynthesis & if a thing uses something that comes from a source then that thing uses the source of that something2 ->  green plant uses sunlight for photosynthesis  green plants make food by performing photosynthesis & green plant uses sunlight for photosynthesis ->  a green plant uses sunlight to make food  if a thing uses something that comes from a source then that thing uses the source of that something & if a thing uses something that comes from a source then that thing uses the source of that something1 ->  if a thing uses sunlight then that thing uses the sun  a green plant uses sunlight to make food & if a thing uses sunlight then that thing uses the sun ->  a green plant uses the sun to make food  a green plant uses the sun to make food & green plants are a kind of producer -> food is a source of energy for producers0: a producer uses the sun to make food  food is a source of energy for producers0 & producers can get energy from food -> producers get energy by using the sun to make food