听下面一段材料,回答第1至4题。 1. According to the passage you've heard, high expectations _____. A. can lead to success B. bring about low hope C. may not be a good thing 2. Why are the Danes a happy people? A. Their expectations are low. B. They live easy lives. C. They gain a lot. 3. What is NOT mentioned in the passage? A. Higher life satisfaction in Denmark. B. The importance of health. C. Factors of happiness. 4. What is the talk mainly about? A. High expectations. B. Happiness. C. The key to happiness.