A、It is the oldest bridge in New York. B、It is the first suspension bridge built in the USA. C、It is the first suspended railway

Manhattan Island is surrounded on the east by the East and Harlem Rivers and on the west by the North and Hudson Rivers. It links with the other four towns which make up New York City and with New Jersey by means of subways, underground tunnels and bridges which lead into Manhanttan from the surrounding area.
    The Brooklyn Bridge was the first suspension bridge to link Brooklyn to Manhanttan. It is also the second oldest bridge in New York. The architect was John Augustus Roebling, who was the chief engineer of the suspended Railroad Bridge at Niagara Falls.
    Misfortune accompanied the building of the bridge, which took place from 1869 to 1883. The architect died as a result of an accident early during the construction. His son, Washington Roebling, carried on his father’s work, using the most advanced engineering techniques of the day. He also fell ill during the construction of the bridge and was obliged to direct the work on it from an apartment window overlooking the site.
    Since its construction the Brooklyn Bridge has remained a busy and important passage in New York. The Brooklyn Bridge is 6,775 feet long and 1,595 feet wide. The suspended part is 3,450 feet long and 85 feet wide. It has a clearance of 133 feet above water level. Four huge cables extend across the bridge, supported by two towers, each 272 feet high. Each of these cables is made up of 5,700 wires.
Questions 29 to 31 are based on the passage you have just heard.
29. What do we know about the Brooklyn Bridge?
30. What do we learn about in the course of the construction of the bridge?
31. What was Washington Roebling forced to do?