A、Ill luck. B、Evil spirits. C、Filthy food. D、Viruses. B

In ancient societies sick people had to rely on medicine men and witch doctors. (Some people still rely on them.) It was believed that a person was sick because he had been attacked by evil spirits. The witch doctor’s job was to drive off those spirits. His technique involved a combination of three methods. The first method was religious. He chanted magic words and good luck charms. He thought these words and charms had the power over the evil spirits. Secondly, he fed the patient some mixtures. These mixtures were often filthy and disgusting, to make the evil spirits so uncomfortable that they would gladly run away.
    The third method was to give the patient medicines prepared from certain plants and herbs. From our point of view, this was the only method that had any value. Modern scientific study has shown that some of these remedies had real usefulness in curing sickness or relieving pain.