28. According to the passage, we often appreciate our friends .
C. only when they passed away
29. We do not take care of our health because .
C. we are so accustomed to good health
30. Poor health makes us .
B. unable to fulfill our expectations
31. According to the author, having plenty of sleep when we are young .
B. can help us regain our strength
32. The best title for the passage is .
D. The Value of Health