听力原文： Most industrialized nations have gone through two major energy transitions. By e

nergy transition we mean a change from one major source of energy to another.

The first major energy transition was from wood to coal. For many centuries people used wood as a primary source of energy. By burning wood people were able to heat their homes, cook their food, and produce basic items. Most early societies grew up near a sufficient supply of wood. The main advantage of wood was that it was easy to get and easy to bum.

During the early 1800's, some towns and villages began to make a transition from wood to coal as a basic source of energy, because they found that coal generally burns longer and at a higher temperature than wood, and a long-burning and hot-burning fuel was badly needed for the machines that were being used at that time. Another advantage of coal was that there was a lot of it and it was also easy to get. Besides, it could be easily shipped to faraway places.

As a result of the transition from wood to coal, industry developed very rapidly. People were able to get more things and their standard of living went up.

The second major energy transition was from coal to oil. We'll discuss it next week.

Why did most early societies grow up near a sufficient supply of wood？

A．Because wood was safer than coal.

B．Because wood burned longer than coal.

C．Because there was more wood than coal.

D．Because they used wood as primary source energy.