With limited ____ resources, it is hardly possible for them to start a business of their own. （）

Work is a very important part of life in the United States. Americans spend most of their lives working. For most Americans, their work defines them. They are what they do. What happensd, then, when a person can no longer work?

Most Americans stop working at the age of sixty-five or seventy and retire. Because work is such an important part of life in American culture, retirement can be very difficult for Americans. Retirees often feel that they are useless and unproductive. Of course, some people are happy to retire, but leaving one's job, whatever it is, is a difficult change, even for those who look forward to retiring. Retirement can also bring financial problems. Many people depend on Social Security checks every month. During their working years, employees contribute a certain percentage of their salaries to the government. Each employer also gives a certain percentage to the government. When people retire, they receive this money as income. Sometimes these checks do not provide enough money to live on, because prices are prone to increasing, a process known as "inflation". Senior citizens, those over sixty-five, typically have to have savings in the bank or other retirement plans to make ends meet. In addition, many senior citizens have to change their lifestyles after retirement. They have to spend carefully to be sure that they can afford to buy food, fuel and other necessities(必需品).

Of course, many senior citizens are happy with their retirement. They have time to spend with their families or to enjoy their hobbies. Some continue to work part-time, others do volunteer work. Some, like those in the Retired Business Executives Association, even help young people to start new businesses. Many retired citizens also belong to "Golden Age" groups. These organizations plan trips and social events. There are many other opportunities for retirees.

Which of the following could be the best title of the passage?

A．Golden Age Groups

B．The American Opinion of Work

C．The Importance of Work in America

D．The Problems of Retirement in America

The most aggressive of the four eastern-slope species is the lodgepole chipmunk, a feisty rodent indeed. It actively prevents alpine chipmunks from moving downslope, and yellow pine chipmunks from moving upslope. There is logic behind the lodge-poles aggressive demeanor. It lives in the cool, shaded conifer forests, and of the four species, it is the least able to tolerate heat stress. It is, in other words, the species of the strictest habitat needs: it simply must be in those shaded forests. However, if it shared its habitat with alpine and yellow pine chipmunks, either or both of these species might outcompete it, taking most of the available food. Such a competition could effectively eliminate lodgepole chipmunks from the habitat. Lodgepoles survive only by virtue of their aggression.

According to paragraph 6, why is the lodgepole chipmunk so protective of its habitat from competing chipmunks?

A．It has specialized food requirements.

B．It cannot tolerate cold temperatures well.

C．It requires the shade provided by forest trees.

D．It prefers to be able to move between areas that are downslope and upslope.

Which of the following rifles is the most appropriate for the passage?

A．In Defense of the Gum.

B．A Sharp Word for the Guru.

C．the Weakness of the Gum,

D．Gums—a Guarantee for Success.

Which of the following titles is the most appropriate for the passage?

A．In Defense of the Guru.

B．A Sharp Word for the Guru.

C．the Weakness of the Guru.

D．Gurus — a Guarantee for Success.