题目内容：

Researchers found that people become happier and experience less worry after they reach the age of fifty. In fact, they say by the age of eighty-five, people are happier with their life than they were when they were eighteen years old.

Arthur Stone in the Department of Psychiatry and Behavioral Science at Stony Brook University in New York led the study. His team found that levels of stress were highest among adults between the ages of twenty-two and twenty-five. The findings showed that stress levels dropped sharply after people reached their fifties. Happiness was highest among the youngest adults and those in their early seventies. The people least likely to report feeling negative emotions were those in their seventies and eighties.

The findings appeared in the Proceedings of the National Academy of Sciences. Researchers say they do not know why happiness increases as people get older. One theory is that, as people grow older, they grow more thankful for what they have and have better control of their emotions. They also spend less time thinking about bad experiences.

The researchers considered possible influences like having young children, being unemployed or being single. But they found that influences like these did not affect the levels of happiness and well-being related to age.

The study also showed that men and women have similar emotional patterns as they grow older. However, women at all ages reported more sadness, stress and worry than men.

1. What is the best title of the passage?

A. The older a person is, the more stressed he feels.

B. The more lighthearted a person is, the happier he is.

C. The older a person is the more clever he grows.

D. The older a person is, the happier he grows.

2. We can learn from the research that _________.

A. only when people get older, will they feel happier

B. older people usually have no worries in their life

C. stress levels among the youngest are the highest of all

D. older people are more likely to be thankful in life

3. According to the researchers, what is probably the reason why people grow happier when they get older?

A. When people get older, they can’t remember bad experiences.

B. When people get older, they have no young children to care about.

C. When people get older, they learn to adjust their feelings.

D. When people get older, they don’t care about their feelings.

4. What would the writer probably deal with in next paragraph?

A. Advice to the young people on how to keep happy.

B. Advice to the old people on how to live longer.

C. Why women at all ages are more sad, stressed and worried.

D. Why people will grow happier with their ages.