听力原文： The first man who cooked his food, instead of eating it raw, lived so long ago t

hat we have no idea who he was or where he lived. We do know, however, that for thousands of years, food was eaten cold and raw. Perhaps the first cooked food was heated accidentally by a forest fire or by the molten lava from an erupting volcano. No doubt, when people first tasted cooked food, they found it tasted better. However, even after this discovery, cooked food must have remained a rarity until man learned how to make and control fire.

Early people who lived in hot regions could depend on the heat of the sun to cook food. For example, in the desert areas of the southwestern United States, the Indians cooked their food by placing it on a flat stone in the hot sun. They cooked pieces of meat and thin cakes of corn meal in this fashion.

We can assume that the earlier kitchen utensil was a stick to which a piece of meat could be attached and held over a fire. Later this stick was replaced by an iron rod which could be turned frequently to cook the meat on all sides. Cooking food in water was impossible before man learned to make water containers that could not be destroyed by fire.

All of man' s history has been shaped by his search for food. Man' s first occupation was of that of a hunter, and his first stone weapons were made for hunting. Then man learned to grow plants for food.

They began to settle in communities next to their fields. More people lived in the places where food was more available. Progress has been greater in these parts of the world where there is more food to eat.

In which way may the first cooked food be made？

A．It was accidentally baked on volcanoes.

B．It was cooked by forest fire by chance.

C．It was boiled in the natural hot-water spring.

D．It was cooked by the heat of the sun.