`29.`B it does not make them carry the weight of their body on their feet
`→`Dẫn chứng : Because you’re not carrying the weight of your body on your feet, it’s a good form of exercise for people with painful feet or backs.
`30.`A gradually
`→`Dẫn chứng : However, with all forms of exercise it’s important to start slowly and build up gently.
`31.`B at least two or three times a week
`→`Dẫn chứng : Ideally you should be cycling at least two or three times a week.
`32.`D Making you look younger
`→`Dựa vào nội dung của toàn bài ta có thể kết luận đáp án D không có trong những ưu điểm của việc đạp xe.