29B. it does not make them carry the weight of their body on their feet (dòng 5-6: “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.”)
30A. gradually (adv: một cách từ từ; dòng 7: “…with all forms of exercise it’s important to start slowly…”)
31B. at least two or three times a week (câu đầu đoạn 2: “…Ideally you should be cycling at least two or three times a week.”
32C. it is a sign of exercise having the right effect (dòng 5: “…shortness of breath shows that the exercise is having the right effect)
33D. Making you look younger
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