Light from the stars, because the orbits make it difficult to see them.
Answer:
Interface
Explanation:
This is a classic example of Interface technology.
An interface allows different software packages to communicate without re-entering data.
Here in this case also systems are able to communicate with one another without duplicating data entry. For example, practice management software and another for their electronic health record.
1) use energy from food
2) get rid of wastes
3) maintain
