问题 单项选择题

下面对对象概念描述错误的是 ( )

A.任何对象都必须有继承性

B.对象是属性和方法的封装体

C.对象间的通讯靠消息传递

D.操作是对象的动态属性

答案

参考答案:A

解析: 继承是面向对象的方法的一个主要特征。继承是使用自己有的类定义作为基础建立新类的定义技术。已有的类可当做基类来引用,则新类相应地可当做派生类来引用。但并不是所有的对象都必须有继承性。因此,选项A中的说法是错误的。

单项选择题
单项选择题

Listen carefully, working people, we would like to tell you something that could save your precious time and money! Best of all, it is free!
It’s "no".
What do you ask We’ll say it again: "No. "
Sweet and simple "no".
Say "no" at your office and see how quickly that pile of work on your desk disappears.
"Saying ’no’ to others means you are saying ’yes’ to yourself, " said Leslie Charles, a professional speaker from East Lansing, Michigan.
"Time is precious. People are spending money buying time. And yet we are willing to give up our time because we can’t say ’no’. "
Susie Watson, a famous writer, said people who always say "yes" need to say "no" without guilt or fear of punishment. "I would rather have someone give me a loving ’no’ than an obligated ’yes’, " she said.
Susie Watson says she feels "no" obligation to give an explanation when she says "no" either socially or professionally. Does she feel guilty about it "Not at all, " said Watson, who is director of advertising and public relations at Timex Corp in Middlebury, Conneticut. "Most people are afraid of saying ’no’... My advice is to say ’yes’ only if you don’t mean ’no’. "
Watson said "no" is the most effective weapon against wasting time. "Every year there are more demands on your time... Other people are happy to use up your time, " Watson said. Time saving appears to be "no’s" greatest friend.
"No" can be your new friend, a powerful tool to take back your life. "No" may even take you further in the business world than "yes".
"No" is power and strength. "No" now seems completely correct. "Saying ’no’ isn’t easy. But finally it’s greatly liberating, " Charles said. But, he added, "a ’no’ project needs to be worked on every day because it is hard to change long-term habit. "
But, he also warns: "Don’t go to extremes. Don’t find yourself saying ’no’ to everything. In return you should learn to hear ’no’. \

In Watson’s opinion, people can save much time on condition that ______.

A. they say "no" at a suitable time
B. they say "no" as much as possible
C. they are afraid of saying "no"
D. they make others angry at them