Part 4: 1. Last weekend, my parents have picked wild mushrooms -> Correct: Last weekend, my parents picked wild mushrooms. 2. Tom worked very hard since he moved to Ha Noi. -> Correct: Tom has worked very hard since he moved to Ha Noi. 3. He died after suffing of a serious illness. -> Correct: He died after suffering from a serious illness. 4. You will become healthy if you eat a lot of snacks. -> Correct: You will not become healthy if you eat a lot of snacks. 5. Keep healthy by eating well and exercising regular. -> Correct: Keep healthy by eating well and exercising regularly. 6. I completely avoid to eat cake. If I eat cakes, I'll awfuul. -> Correct: I completely avoid eating cake. If I eat cakes, I'll feel awful. 7. Having a balancing diet is very important for a long and healthy life. -> Correct: Having a balanced diet is very important for a long and healthy life. Part 5: 1. My father has not taken exercise so far. 2. Peter has been building muscles since he started working out at the gym. He looks really fit now. 3. When she arrived at the hospital, the doctor saw me. 4. I did exercise with my parents 4 hours ago. 5. My brother spends 3 hours a day taking exercise regularly. 6. She spent many weeks in hospital recovering from her injuries. 7. In the past, health care in some rural areas of this country was provided by only a small number of doctors and nurses. 8. It's taken me a long time to get over the flu. 9. They have not found a cure for cancer yet. 10. How long have you had a headache? I think you should see a doctor.