题目内容：
Osaka(大阪)was Japan’s greatest commercial city in ancient times and is the city with Japan’s biggest castle(城堡).Modern Osaka is a good place to see commercial and industrial Japan.The castle is the most interesting tourist attraction in the city.It was built in 1586.The easiest way to get to Osaka is on the world—famous bullet train(新干线)from Tokyo，which travels over 210 kilometers per hour.It is said to be the cleanest train in the world.
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