题目

The Golden Gate Bridge in San Francisco，California is one of the world's most beautiful bridges. It is also one of the most visited places in the world. Vehicles cross the bridge an average of 41 million times each year. More than 1800 hundred million vehicles have used the bridge since it opened more than 70 years ago.    The bridge was painted “International Orange” because that color went well with the natural surroundings. The color also is easier to see in the heavy fog that often covers the area. But the Golden Gate Bridge was not named for its orange color. It was named fo14．一艘轮船从青岛到上海，每小时行12.5千米，24小时到达．如果每小时行15千米，需要多少小时到达？