A、Cycling around a lake. B、Motor racing in the desert. C、Playing basketball in a gym. D、Swimming in a sports center. A选项均以动词-ing

Sports can help you keep fit and get in touch with nature. However, whether you are on the mountains, in the waves, or on the grassland, you should be aware that your sport of choice might have great influence on the environment.
    Some sports are resource-hungry. Golf, as you may know, eats up not only large areas of countryside, but also tons of water. Besides, all sorts of chemicals and huge amounts of energy are used to keep its courses in good condition. This causes major environmental effects. For example, in the dry regions of Portugal and Spain, golf is often held responsible for serious water shortage in some local areas.
    There are many environment-friendly sports. Power walking is one of them that you could take up today. You don’t need any special equipment except a good pair of shoes; and you don’t have to worry about resources and your purse. Simple and free, power walking can also keep you fit. If you walk regularly, it will be good for your heart and bones. Experts say that 20 minutes of power walking daily can make you feel less anxious, sleep well and have better weight control.
    Whatever sport you take up, you can make it greener by using environment-friendly equipment and buying products made from recycled materials. But the final goal should be "green gyms". They are better replacements for traditional health clubs and modern sports centers. Members of green gyms play sports outdoors, in the countryside or other open spaces. There is no special requirement for you to start your membership. And best of all, it’s free.
Questions 29 to 32 are based on the passage you have just heard.
29. Which is the speaker most probably in favor of?
30. What do we know about golf from the passage?
31. Why does the speaker use power walking as an example?
32. What is the speaker’s main purpose of giving this speech?