Pictures of animals were painted on the walls of caves in France and Spain because ______.

People have been painting pictures for at least 30,000 years. The earliest pictures were painted by people who hunted animals. They used to paint pictures of the animals they wanted to catch and kill. Pictures of this kind have been found on the walls of caves in France and Spain. No one knows why they were painted there. Perhaps the painters thought that their pictures would help them to catch these animals. Or perhaps human beings have always wanted to tell stories in pictures.
    About 5,000 years ago, the Egyptians and other people in the New East began to use pictures as a kind of writing. They drew simple pictures or signs to represent things and ideas, and also to represent the sounds of their language. The signs these people used became a kind of alphabet.
    The Egyptians used to record information and to tell stories by putting picture-writing and pictures together. When an important person died, scenes and stories from his life were painted and carved on the walls of the place where he was buried. Some of these pictures are like modern comic strip stories. It has been said that Egypt is the home of the comic strip. But, for the Egyptians, pictures still had magic power. So they did not try to make their way of writing simple. The ordinary people could not understand it.
    By the year 1,000 B.C., people who lived in the area around the Mediterranean Sea had developed a simpler system of writing. The signs they used were very easy to write, and there were fewer of them than in the Egyptian system. This was because each sign, or letter, represented only one sound in their language. The Greeks developed this system and formed the letters of the Greek alphabet. The Romans copied the idea, and the Roman alphabet is now used all over the world.
    These days, we can write down a story, or record information, without using pictures. But we still need pictures of all kinds: drawing, photographs, signs and diagrams. We find them everywhere: in books and newspapers, in the street, and on the walls of the places where we live and work. Pictures help us to understand and remember things more easily, and they can make a story much more interesting.