6. Underline the correct one. 1. I always feel very tired and I have a terrible backache. I think I should / shouldn't work long hours. 2. Mary wants to lose weight and be healthy. She should / shouldn't do exercise. 3. My grandfather has a terrible headache. He should / shouldn't take some medicine. 4. Daniel has a high temperature. He should / shouldn't go to school today. 5. Our teacher has a sore throat. a . He should / shouldn't have cold drinks.​