Tokyo, the capital of Japan, is one of the largest cities in the world. It is also one of the world's most modern(现代化的)cities. Twice this century, the city was destroyed and rebuilt. In 1923 a major earthquake struck the city. Thousands of people were killed and millions were left homeless as buildings collapsed(倒埸)and fires broke out throughout Tokyo. It took seven years to rebuild the city. During World War Ⅱ ,Tokyo was destroyed once again. As a result of these disasters(灾难), there is nothing of old Tokyo remaining in the downtown area. After the war, the people of Tokyo began to rebuild their city. Buildings went up at a fantastic(令人惊奇的)rate, and between 1945 and 1960, the city's population more than doubled. Because the Olympic Games held in Tokyo in 1964, many new stadiums(体育场), parks and hotels were built to accommodate(供给……住宿)visitors from all over the world. As a result of this rapid development, however, many problems have arisen (出现). Housing shortage (缺乏), pollution and waste disposal(处理) have presented serious challenges(挑战) to the city, but the government has begun several programs to answer them. What kind of city is Tokyo?