For the most part, rapid economic development has been a favor. But there is a down side to development -- health problems such as overweight are all becoming more common, as more people take taxis to work instead of riding their bicycles, and other labour-saving devices become more popular. An increasingly fast pace of life makes it difficult for people to spend time playing sports. “I know exercise is good for your health,” a young lady said. “ But after a busy work week, the only thing I want to do is watch some TV and go to sleep.” That attitude may explain the results of a recent nationwide study, which suggested 15 percent of s in China have heart problems. Local researchers found that 31. 2 percent of elderly respondents (受访者) were getting enough exercise, but less than 9 percent of youngsters and the middle-aged got enough physical activity. Elderly people understand the importance of protecting their health. The young people, however, are busy working and use this as an excuse
Rapid economic development has resulted in all the following EXCEPT（）.