听力原文： Cats never fail to fascinate human beings. They can be friendly and affectionate towards humans, but they lead mysterious lives of their own as well. They never become submissive like dogs and horses. As a result, humans have learned to respect their independence. Most cats remain suspicious of humans all their lives. One thing that fascinates us most about cats is the popular belief that they have nine lives. Apparently, there is a good deal of truth in this idea. A cat's ability to survive falls is based on fact.
Recently the New York Animal Medical Centre made a study of 132 cats over a period of five months. All these cats had one experience in common: they had fallen off high buildings, yet only eight of them died from shock of injuries. Of course, New York is the ideal place for such an interesting study, because there is no shortage of tall buildings. There are plenty of high-rise windowsills to fall from! One cat, Sabrina, fell 32 stories, yet only suffered from a broken tooth. "Cats behave like well-trained paratroopers," a doctor said. It seems that the further cats fall, the less they are likely to injure themselves. In a long drop, they reach speeds of 60 miles an hour and more. At high speeds, falling cats have time to relax. They stretch out their legs like flying squirrels. This increases their air-resistance and reduces the shock of impact when they hit the ground.
(33)

A. Because cats always fascinate human beings.
Because cats are friendly and affectionate towards humans.
C. Because there is a popular belief that cats have nine lives.
D. Because cats lead their own lives and seldom become obedient like dogs are.