问题 单项选择题

回归测试是下列哪项维护工作中最常用的方法

A.适应性维护

B.校正性维护

C.完善性维护

D.预防性维护

答案

参考答案:B

解析: 软件维护有四种类型:校正性维护、适应性维护、完善性维护和预防性维护。其中: ·校正性维护是指对在测试阶段没有发现的错误进行测试、诊断、定位、纠错及验证修改的回归测试过程。 ·适应性维护是指为了使软件系统适应不断变化的运行环境而修改软件的过程。 ·完善性维护是指软件投入使用并成功运行后,根据用户关于增加新的处理功能,修改原有功能以及各种改进的要求或建议,对该软件系统的功能和质量做进一步的修改或补充。 ·预防性维护是指为了改良将来的可靠性或可维护性,或者为将来的改进奠定更好的基础,而对软件进行的修改或补充。

阅读理解

阅读理解

     British scientists may have discovered the reason why red wine appears to protect the heart. They

say natural chemicals found in red wine appear to protect against blocked blood vessels(血管). The

chemical substances are called poly-phenols(多酚). They come from the outer covering of grapes. They

are not present in other alcoholic drinks.

     Researchers say their discovery explains why many people in southern Europe can eat fatty foods and

still have a low risk of heart disease. People in France, for example, have lower rates of heart disease

than Americans do. Yet the traditional French diet includes butter, cheese and other foods high in

cholesterol(胆固醇). This led the British scientists to examine another important part of the French

diet - red wine. Several earlier studies have suggested that people who drink proper amounts of alcohol

may reduce their risk of heart disease.

     The British team experimented with cells from the blood vessels of cows. The scientists studied the

effects of twenty-three kinds of red wine on the cow cells. They found that poly-phenols from all of the

red wines stopped production of a protein called endothelin(内皮素). This protein causes blood vessels

to become smaller. Scientists believe endothelin is linked to hardening of the blood vessels, which is a

cause of heart disease.

    The scientists found that the decrease in endothelin levels was linked to the amount of poly-phenols in

the wines. The British team performed similar experiments with two other kinds of wine, white and rose.

These wines contain little or no poly-phenols because the grape skins are removed before the wine is

made. White and rose wines had no effect on endothelin levels.

     The scientists also studied the effect of non-alcoholic juice made from red grapes. They found that

grape juice slowed the production of endothelin, but was much less effective than the red wines.

1. So far as grapes are concerned,           is more effective on reducing the risk of heart disease.

A. the outer part of grapes

B. the inner part of grapes

C. the seeds of grapes

D. the juice in grapes

2. What made the British scientists study another important part of the French diet?

A. Traditional French diet.

B. Lower risk of heart disease of the French.

C. The reason why people drink wine.

D. Poly-phenols not existing in other things.

3. From this passage, we may know people's health is linked to           .

A. diet habits  

B. their genes

C. their education

D. living surroundings

4. What's the best title for this passage?

A. A Healthy Diet

B. Protecting Your Heart

C. Red Wine and Health

D. A Study on Health

名词解释