A、Buses, B、Bicycles. C、Unlicensed vehicles. D、Private cars. D根据题干中关键词找到听的重点部分。

For five years I lived in Singapore, a metropolis of almost three million people. Like London, Paris and New York, Singapore is a cosmopolitan city, with people from different parts of the world living and working together. I enjoyed the urban lifestyle I led there, and made the most of the super amenities, ranging from the excellent shops to some of the best restaurants in the world.In the evenings and at weekends there were always cultural events, with such diverse attractions as classical Western music, and exhibition of Malay art or a Chinese opera in the street, it was difficult to get bored.Perhaps most impressive, however, was the remarkable transport infrastructure, with excellent roads, a swift and efficient bus service and a state-of-the-art underground system which could whisk commuters from the suburbs straight into the heart of the city. This is particularly important, as the government banned private cars from entering the central business district during the morning and afternoon rush hours to reduce congestion on the roads and pollution from the exhausts.
Of course, living in a city like this has its disadvantages as well. For a start, the cost of living can be very high -- renting an apartment, for example, is very expensive. And as the city is expanding, there are a lot of building sites Where new apartments are continually being built to deal with the population explosion which is a direct result of the government encouraging people to have more children.