A、Bends. B、Tiredness. C、Dehydration. D、Lack of oxygen. A

SW: Good evening, this is Sports World greeting you here at 20:30 GMT. Have you ever participated in a risky sport? What was it? In today’s program we have Jenny Adams, a very athletic woman to talk to us about risky sports. Hang gliding is a dangerous sport. Jenny, what do you enjoy about the sport, and have you ever had an accident?
   Jenny: No, I’ve never been seriously injured. Maybe I’ve just been lucky. Once my glider turn upside down, and I lost control. I almost crashed, but I parachuted away just in time. And I’ve always felt hang gliding is quite safe—though landing is sometimes difficult. But it’s fantastic to be able to fly like a bird!
   SW: And you’ve been mountain climbing for years now, right? What is the most difficult part?
   Jenny: Yes, I’ve been mountain climbing for 3 years, and the toughest part I believe is the high altitudes. They could be rather hard on the human body. I’ve experienced lack of oxygen, tiredness, and dehydration. I’ve lived through storms, avalanches, and strong winds. But that’s what I like about mountain climbing—overcoming danger.
   SW: What exactly are the bends? And have you ever experienced them while scuba diving?
   Jenny: You get the bends when you’ve been deep under water. If you come up out of the water too quickly, bubbles form in your blood. The bends can be serious, and they can even cause death. But the bends are rare. Scuba diving isn’t really dangerous. And it lets you explore another world.
   SW: Thank you Jenny for join us in the talk. And next time we’ll have Tom Barker to share with us his story in white-water rafting, and bungee jumping.
27.How many kinds of risky sports are Jenny doing?
28.What’s the most difficult part in mountain climbing according to Jenny?
29.Which of the following is NOT one of the dangers of mountain climbing?
30.Which of the following is NOT true for bends?