Among rich countries, people in the United States work the longest hours. They work much longer than in Europe. This difference is quite surprising because productivity(生产力) per hour worked is the same in the United States as it is in France, Spain and Germany, and it is growing at a similar speed.
In most countries and at most times in history, as people have become richer they have chosen to work less. In other words they have decided to “spend” a part of their extra income on a fuller personal life. Over the last fifty years Europeans have continued this pattern, and hours of work have fallen sharply. But not in the United States. We do not fully know why this is. One reason may be greatly lower taxes in America, which increase the rewards to work. Another may be more satisfying work, or less satisfying personal lives.
Longer hours do of course increase the GDP(国内生产总值). So the United States has produced more per worker than, say, France. The United States also has more of its people at work, while in France many more mothers and older workers have decided to stay at home. The overall result is that American GDP per head is 40% higher than in France, even though productivity per hour worked is the same.
It is not clear which of the two situations is better. As we have seen, work has to be compared with other values like family life, which often get lost in its interest. It is too early to explain the different trends（趋势）in happiness over time in different countries. But it is a disappointing idea that in the United States happiness has made no progress since 1975, while it has risen in Europe. Could this have anything to do with trends in the work-life balance?
Which of the following countries has more of its people at work?

A．Spain.

B．France.

C．Germany.

D．America.

What message can we get from the text?

A．The GDP of Europe is higher than that of America.

B．Two possible reasons are given for working longer hours in the US.

C．People all over the world choose to work less when they are richer.

D．Americans are happier than Europeans.

Which of the following would be the best title for the text?

A．Americans and Europeans

B．Staying at Home

C．Work and Productivity

D．Work and Happiness