Identify the topic sentences of the following paragraphs. You may either find it in the paragraph directly or summarize the topic sentence in your own words. There are now over 700 million motor vehicles in the world – and the number is rising by more than 40 million each year. The average distance driven by car users is growing too – from 8 km a day per person in western Europe in 1965 to 24 km a day in 1995. This dependence on motor vehicles has given rise to major problems, including environmental pollution, depletion of oil resources, traffic congestion and safety (TS).