Make the question for the underlined part. 1. People can avoid some diseases by keeping themselves clean. (phần gạch chân từ by đến clean) 2. Her brother should take part in volunteer activities. (gạch chân từ take đến activities) 3. Jimmy has flu because he keep sneezing and coughing (gạch chân từ becaue đến coughing) 4. The students often help elderly people to sweep the house and cook meals.(gạch chân từ to đên hết) 5. They wen swimming two hours ago. ( gạch chân từ two đến hết) 6. Nam and Lan often donate books to street children.(gạch chân từ street đến hết) 7. My Mum thinks that ice-skate is difficult. (gạch chân từ difficult)