听力原文：

W: Right behind me is the Brooklyn Bridge. This is often called New York City's most beautiful bridge. It was completed in 1883 and it took fifteen years and cost 15 million dollars to build. When it was built, it was the world's longest suspension bridge. These two towers were just about the tallest structures in the city at that time.

M: Who designed the bridge?

W: The bridge was designed by John Roebling, but he died after an accident early in the project. It was his son Washington Roebling who actually managed and completed the project. It was a huge project and quite dangerous

M: Why? Did people fall from the bridge?

W: Actually, the main danger was decompression sickness.

M: What's that?

W: Decompression sickness is what happens when you come back up from being deep underwater. The two towers had to be sunk into the mud at the bottom of the river, so workers had to work down there. They were lowered into the water in large wooden boxes. Coming back up, they got air bubbles in their bloodstream. Several of the workers died or became ill from that.

M: Wow!

W: Washington Roebling himself got sick in the middle of the project and he couldn't continue. He had to stay in bed, so he directed the rest of the project from his bedroom window, using a telescope. He dictated his orders to his wife, and she told the workers what to do.

M: That's an incredible story. Was this the first bridge across the river?

W: It was, so it was very important, and a lot of people used it. It cost a penny per person - one cent - to walk across the bridge, and ten cents to drive a one-horse wagon across. Five cents for a horse or a cow.