问题 单项选择题

如果要将窗体中的某个命令按钮设置成无效状态,应该动命令按钮的何种属性?

A.报表只能输入数据

B.报表只能输出数据

C.报表可以输入和输出数据

D.报表不能输入和输出数据

答案

参考答案:B

解析:数据封装就是数据抽象;友元可以访问类中的所有成员,是面向对 象的一个重要特征,但是破坏了封装性;重载和动态联编都是面向对象的另一个特点-- 多态性。

多项选择题
阅读理解

阅读理解。

     Most people look forward to retirement as a time when they can finally take up activities that they never

had the time or energy to pursue before. But some recent studies on people in their golden years are disturbing:

they suggest that retirees are more likely to suffer from depression and possibly higher rates of other diseases

such as heart disease and high blood pressure. That's why a new study of French workers is welcome news.

     Led by Hugo Westerlund, a professor of psychology at Stockholm University, the study of more than

14,000 workers found lower rates of depression and fatigue (疲劳) in people after they got retired while they

were still employed.

     The scientists followed employees of the French National Gas and Electric Company for 14 years. They

found in the year immediately after retirement, the volunteers reported 40% fewer depressive symptoms than

they had in the year before their retirement. The researchers also found an 81% drop in reports of both mental

and physical fatigue over the same time period.

     Clearly, said Westerlund, much of these decrease in physical and mental fatigue can be traced back to relief

from the stresses of work. The decline in depressive symptoms suggests that retirement may be having a

positive mental effect, too, which may have a lot to do with the generous pensions (养老金) that French

workers enjoy. Most retirees in that country still benefit from about 80% of their yearly salaries.

     "The economic or financial situation in retirement is very important," Westerlund says. "We don't know if

the decrease in fatigue and depressive symptoms is because of the removal of something bad while in work

or the addition of something good while in retirement. But no matter the reason, if life in retirement is not

comfortable, then we won't see the improvements we did."

     However, in European nations like France, governments are considering changes to pension plans, which

may affect retirees' health after they leave their jobs-with less of a financial safety net, workers may no longer

seem so mentally and physically happy to be out of work.

(Note: Answer the questions or complete the statements in NO MORE THAN EIGHT WORDS.)

1. According to some recent studies, retired people may have depression and higher rates of other diseases

    like _______.

2. Westerlund's group found that in the year just after the retirement most retired French workers felt much less

    tired both _______.

3. What does the word "improvements" in paragraph 5 refer to? 

    ________________________________________________________________________________________

4. Retirement may make people happier with ______.