【英语时差8,16】时间之谜--日历的产生（在线收听）

Early humans hunted animals and gathered wild plants. They moved in groups or tribes from place to place in search of food. Then, people learned to plant seeds and grow crops. They learned to use animals to help them work, and for food. They found they no longer needed to move from one place to another to survive. As farmers, however, they had to plant crops in time to harvest them before winter. They had to know when the seasons would change. So, they developed calendars. When people started farming, the wise men of the tribes became very important. They studied the sky. They gathered enough information so they could know when the seasons would change. They announced when it was time to plant crops. The divisions of time we use today were developed in ancient Babylonia four-thousand years ago. Babylonian astronomers believed the sun moved around the Earth every three-hundred-sixty-five days. They divided the trip into twelve equal parts, or months. Each month was thirty days. Then, they divided each day into twenty-four equal parts, or hours. They divided each hour into sixty minutes, and each minute into sixty seconds.