----- Nội dung dịch tự động từ ảnh ----- XV. Change into the passive voice: 1. The scientists are carrying out an important experiment. 2. People make cheese from milk. 3. Did Wright brothers build the first plane in 1903? 4. Witcomb L. Judson invented the zipper in 1893. 5. People have used the ballpoint pens for many years. 6. They will publish a book on space travel next month.
