They needed to trade with others nearby to get all of the resources they needed. They had to rely on the sea, so they became good fishers, sailors, and traders.
The Greeks had to raise crops and animals suited to the hilly environment and the climate of hot, dry summers and wet winters. Their crops were wheat, barley, olives and grapes.
Answer: The glacial-interglacial cycle is triggered by changes in Earth's orbit around the Sun, and, as a result, there is approximately 100,000 years between interglacials (or glacials).
