读美国本土略图，回答问题．

   Americans love sports . But this hobby sometimes has serious results—at least to the players. For example, when people play tennis, sometimes they hurt their elbow（肘部）. Also it is easy to hurt a knee in a football game. These injuries（毁伤）happen while the player is having fun, but they still hurt.
   A few months ago, Kathleen Simmons, who loves playing volleyball, hurt her knee in a volleyball game. Her doctor told her that she needed a very difficult operation（手术）or she might not be able to play again. She felt very sad
   Then Simmons learned about “video operation”. With the help of this new science in medicine, doctors can now repair many injuries.
For this operation, her doctor didn’t have to open her knee. Instead he put a very small camera lens（镜头）inside her knee. The lens sent back pictures, which appeared on a television screen. As he worked, he could see the inside of her knee on the TV. With the help of the large pictures on the screen, the doctor knew exactly what to do when he was making the repairs.
   Simmons started walking five days after her operation. “My knee hurt a lot the first few days,” she said. “But I felt better very quickly.” Now, six months after her operation, Simmons can do everything she did before her injury. “It feels like a new knee,” she said. “I can even play volleyball again.”

    Hello, listeners. Welcome to Henton Hospital Radio. Before our music program begins, I'm going to repeat some of our hospital rules.

    The hospital can sleep 800 patients. There are 8 beds in each ward（病房). The visiting hours are in the afternoon from 2: 30 to 3: 30 and in the evening from 7: 00 to 8: 00. But remember only two visitors at a time. Sorry about that, but you can see what would happen if we didn't have these rules.

    The other rules are about our time schedule. We start quite early-you might not be used to that. We wake you at 6 o'clock, and breakfast is at 8 o'clock, lunch at noon. There's tea at 3:30 and supper is at 6 o'clock.

    You can see the "No Smoking" sign-we don't allow smoking in the wards. I'm sure you understand why. However, if you do need to smoke, there are some smoking-rooms for you.

    You will find the radio switch(开关) on the wall near your bed, with your own headphones, if you want to listen. It's our own hospital radio wishing you a quick recovery(康复).