1. to abstract the idea of greenness from the colour of all green objects 从所有绿色物体中提取出绿的概念
2. All abstract classes must be base classes. 所有的抽象类都应当是基类。
3. All base classes should be abstract classes. 所有的基类都应当是抽象类。
1. a concept or idea not associated with any specific instance
2. a sketchy summary of the main points of an argument or theory v.
1. consider a concept without thinking of a specific example; consider abstractly or theoretically
2. make off with belongings of others
3. consider apart from a particular case or instance
4. give an abstract (of) adj.
1. existing only in the mind; separated from embodiment
2. not representing or imitating external reality or the objects of nature
3. dealing with a subject in the abstract without practical purpose or intention