Hello , Anna . Come in and sit down .   Hello , doctor .   What's the matter ?   I've got a backache .   Do you often suffer from backache ?   No , I don't . I've never had a bad one before .   When did it start ?   About four days ago .   Well , go home and rest in bed for two days , then you'll feel better .   Can you give me some medicine ? It's very painful .   Yes , I'll give you some pills . Take one a time and three times a day , and come back in three days . If you don't feel ... 