I would say camera it was invented by Ibn ul Haitham.
The principle is that what you do to another person, you get done to yourself.
Answer:
The primary group for whom goods and services are produced in a traditional economy is the tribe or family group. In a command economy, the central government decides what goods and services will be produced, what wages will be paid to workers, what jobs the workers do, as well as the prices of goods.
Sorry, but may you add the whole question :(
