题目

阅读理解 Golden Gate Bridge Located in San Francisco,the Golden Gate Bridge started in the year 1933 to connect the San Francisco Peninsula with Marin County.It was finally thrown open to public traffic in 1937.It cost $25.7 million in the construction.Till the year 1957,the Golden Gate Bridge,at a length of 2,737 meters,was the longest suspension bridge in the world. Brooklyn Bridge The Brooklyn Bridge is located in Brooklyn.It is one of the oldest suspension bridges in the United States, having been opened in the year 1883.The length of the bridge is 1,843 meters.The bridge has been feat已知A、B两点分别在直线2x-y=0和x+2y=0上，且AB线段的中点为P（0，5），则线段AB的长为 ．