PowerBuilder是一个
A．用于系统实现阶段的开发工具
B．用于系统详细调查阶段的开发工具
C．用于系统逻辑设计阶段的开发丁具
D．用于系统可行性研究阶段的开发工具
参考答案：D
解析： PowerBuilder是由美国著名的数据库应用开发工具厂商PowerSoft公司于1961年6月推出的完全按照客户机/服务器体系结构设计的快速应用开发系统，是用于系统可行性研究阶段的开发工具。
Nowadays, too much carbon dioxide makes the earth warmer and warmer and causes terrible effect to human beings. To save our planet and ourselves, a new lifestyle called low-carbon life becomes popular. Low carbon means low energy and no waste. It is necessary for everybody to learn to live a low-carbon life. To live a low-carbon life, we’d better save energy as much as possible. Turn off the lights and TV whenever they are not needed. If possible, use cold water to wash clothes or dishes. Take a short shower and try to take a cold one when the weather gets warm. Don’t do the cooking with electricity. To live a low-carbon life, we should eat less meat. Everybody knows eating too much meat makes people fat and easy to have heart disease, but maybe you don’t know keeping animals for food produces even more carbon dioxide than all the cars in the world, and being a vegetarian (素食主义者) can help reduce one and a half tons of carbon dioxide a year. Maybe it is a little difficult, but it’s really necessary. To live a low-carbon life, we are supposed to do less shopping. When we go shopping, we may drive a car or take other transportations (交通工具). On one hand, these machines pollute the air and waste energy. On the other hand, most of us always buy some useless things because of some advertisements. It not only waste money but also causes trouble to the earth, because making everything will produce carbon dioxide more or less. There are many other ways to live a low-carbon life, such as recycling things, planting trees and reusing textbooks. If we can keep it a habit in our daily life, the earth will become a safer planet for us to live on. 任务一：根据短文内容，用简洁的句子或短语完成下列表格。
﹡ 5. |