Can feeling of nostalgia   be good for you? or is it unhealthy to have a strong love for the past? For years, medical experts have studied nostalgia and the reasons for it. Many experts warn that too much nostalgia is harmful. They say linger   in the past shows that a person is unhappy with his present life. These feelings keep the person from living his life to its fullest. Dr. Louise Kaplan has written several books about nostalgia. She says these feelings often begin when a young person is between 13 and 19 years old. "This is the time when you must face the loss of your childhood, " Kaplan says. "You see your new life is easily destroyed. But you think romantically about a golden past. You remember your childhood as a time when life was perfect." These feelings continue as a person gets older, Kaplan adds. She says many grown persons have a hard time keeping up with changes in the modem world, so they think back to their younger years. At that time the world seemed simple and more harmless. Kaplan says these feelings are not always actually existing. The good old days weren't always good. However, she says nostalgia can be helpful, if used properly. "Feelings of nostalgia can cause you to remember a time when you had high hopes and dreams, " Kaplan says. "It might give you the strong wish to catch those dreams today, in your present life." She adds that nostalgia can prevent you from "cutting yourself off from your aim." "At its best, " Kaplan says, "nostalgia has the ideas for the future." The reason for grown persons to think back to their past is that    _   .
they can hardly keep up with changes in today's world times are hard, so they can not keep up with changes many grown persons have little time keeping up with changes in the modem world they lived in the past, of which they are always proud
Question: Can feeling of nostalgia   be good for you? or is it unhealthy to have a strong love for the past? For years, medical experts have studied nostalgia and the reasons for it. Many experts warn that too much nostalgia is harmful. They say linger   in the past shows that a person is unhappy with his present life. These feelings keep the person from living his life to its fullest. Dr. Louise Kaplan has written several books about nostalgia. She says these feelings often begin when a young person is between 13 and 19 years old. "This is the time when you must face the loss of your childhood, " Kaplan says. "You see your new life is easily destroyed. But you think romantically about a golden past. You remember your childhood as a time when life was perfect." These feelings continue as a person gets older, Kaplan adds. She says many grown persons have a hard time keeping up with changes in the modem world, so they think back to their younger years. At that time the world seemed simple and more harmless. Kaplan says these feelings are not always actually existing. The good old days weren't always good. However, she says nostalgia can be helpful, if used properly. "Feelings of nostalgia can cause you to remember a time when you had high hopes and dreams, " Kaplan says. "It might give you the strong wish to catch those dreams today, in your present life." She adds that nostalgia can prevent you from "cutting yourself off from your aim." "At its best, " Kaplan says, "nostalgia has the ideas for the future." The reason for grown persons to think back to their past is that    _   .
A. they can hardly keep up with changes in today's world
B. times are hard, so they can not keep up with changes
C. many grown persons have little time keeping up with changes in the modem world
D. they lived in the past, of which they are always proud
Answer: