Listen to the talk again and complete each sentence with ONE word. (Nghe lại bài nói và hoàn thành mỗi câu với MỘT từ.) 1. Bullet trains will be faster, safer, and riders can avoid traffic … 2. SkyTrans will use less space and run on … 3. SkyTrans may be too … for students. 4. … will be cheaper and easier to use. 5. Solar-powered ships will be … and comfortable.