Rewrite these sentences as directed in brackets: 1.He received a letter from his aunt three days ago.(gạch chân chữ three days ago) =>When...................................... 2.Hoa didn't go to school because she had a headache.(gạch chân chữ because she had a headache) =>Why..................................... 3.She went to the dentist because she had a toothache.(gạch chân chữ because she had a toothache) =>Why.......................................... 4.Her mother often buys food in the supermarket.(gạch chân chữ in the supermarket) =>Where............................ 5.What is his brother's height? =>How....................... 6.Remember to brush your teeth before going to bed. =>Don't..................................