填空 Everyone gets headaches sometimes. But how 46 do you know about headaches? What may cause ( 引起 ) 47 ? And what should we do if we have a headache? 48 should we go to see a doctor? A headache is not a disease ( 疾病 ),but it may show that 49 in our body is wrong. We may have 50 than one headache each month. Usually a fever or some other 51 may cause headaches. We may get a headache when we work too hard. We may get a headache when we don’t get enough 52 .We may get a headache when we exercise on an empty ( 空的 ) stomach. What should we do if we have a headache? We should lie down and rest. We should have a 53 sleep. We shouldn’t take too much exercise if we are 54 . If we have headaches 55 , we need to see a doctor. ( ) 46. A. many B. long C. much D. often ( ) 47. A. it B. this C. that D. them ( ) 48. A. When B. How C. Why D. Where ( ) 49. A. nothing B. anything C. something D. everything ( ) 50. A. less B. more C. little D. most ( ) 51. A. lifestyle B. ways C. medicine D. illnesses ( ) 52. A. money B. sleep C. exercise D. food ( ) 53. A. same B. short C. bad D. good ( ) 54. A. hungry B. thirsty C. tired D. stressed ( ) 55. A. never B. hardly ever C. often D. every month