根据下面资料，回答题 Almost everyone suffers from a headache 21 (occasional). But some people suffer from repeated, frequent headaches. What is headache What causes it What can you do about a headache What research is being done on headaches The dictionary defines headache simply 22 "a pain in the head". 23 most people mean by headache 24 (be) a pain that lasts several minutes or hours. It covers the whole head, or one side of it, or perhaps the front or the back of the head. To add to the confusion about a definition, some people call tight feeling in the head a headache. A headache is important because 25 can be the first warning of a serious condition which probably could be controlled 26 discovered early. If a person 27 (remove) the warning, day after day, with a pain-killer, he may pass the point of easy control. A headache is important also because it disturbs people, 28 (prevent) them from living a happy life. The 29 (employ) with a headache does less work. In a flash of temper he may upset his fellow 30 (guy) or customers, causing a direct or indirect loss to his organization. The mother with a headache suffers and disturbs the family. She upsets her husband and children.