问题 单项选择题

面向对象技术中,______的基本功能,是将一个对象的工作分配到与之相关的更为特殊的对象上,它既可静态定义也可动态定义。

A.继承
B.分类
C.多态
D.委托

答案

参考答案:D

解析: 在面向对象技术中,对已有实例的特征稍作改变就可生成其他的实例的方式称为继承。继承的基本功能是将一些功能相关的对象进行归类表示,使得子对象具有其父对象属性的能力。
分类(Classification)是指对象及其类型之问的关系。
多态是指作用于不同的对象的同一个操作可以有不同的解释,从而产生不同的执行结果。
委托是一种既可静态定义也可动态定义的复杂关系,其基本功能是将一个对象的工作分配到与之相关的更为特殊的对象上。可见,委托使一个对象可以依赖其他对象为它完成某些操作。

单项选择题
单项选择题

Teachers need to be aware of the emotional, intellectual, and physical changes that younga-duhs experience. And they also need to give serious (91) to how they can best (92) such changes. Growing bodies need movement and (93) , but not just in ways that emphasize competition. (94) they are adjusting to their new bodies and a whole host of new intellectual and emotional challenges, teenagers are especially self-conscious and need the (95) that comes from achieving success and knowing that their accomplishments are (96) by others. However, the typical teenage lifestyle is already filled with so much competition that it would be (97) to plan activities in which there are more winners than losers, (98) , publishing newsletters with many student-written book reviews, (99) student artwork, and sponsoring book discussion clubs. A variety of small clubs can provide (100) opportunities for leadership, as well as for practice in successful (101) dynamics. Making friends is extremely important to teenagers, and many shy students need the (102) of some kind of organization with a supportive adult (103) visible in the background.
In these activities, it is important to remember that young teens have (104) attention spans. A variety of activities should be organized (105) participants can remain active as long as they want and then go on to (106) else without feeling guilty and without letting the other participants (107) This does not mean that adults must accept irresponsibility. (108) , they can help students acquire a sense of commitment by (109) for roles that are within their (110) and their attention spans and by having clearly stated rules.

A.On the contrary

B.On the average

C.On the whole

D.On the other hand