问题 单项选择题

以下关于UML状态图的叙述中,不正确的是(13)。对下图的描述正确的是(14)

(14)处填()。

A.ON是一个并发状态

B.因为此状态图中没有终止( final)状态,所以此图是无效的

C.play、stop和rew是动作

D.ON是超状态

答案

参考答案:D

解析:

状态图展现了一个状态机,它由状态、转换、事件和活动组成。状态图关注系统的动态视图,它对接口、类和协作的行为建模尤为重要,它强调对象行为的事件顺序。状态图通常包含简单状态和组合状态、转换(事件和动作)。可以用状态图对系统的动态方面建模。这些动态方面可以包括出现在系统体系结构的任何视图中的任何一种对象的按事件排序的行为,这些对象包括类(主动类)、接口、构件和结点。所以状态图不表示多个对象之间的交互。根据on状态的内部行为可以发现该状态为超状态。

名词解释
阅读理解

阅读理解。

     Do you sometimes argue about what seems to you to be simple fact? Do you argue whether it's cold

outdoors or whether the car in front of you is going faster than the speed limit?

     If you get into such arguments, try to think about the story about the six blind men and the elephant.

The first blind man who felt the elephant's trunk said it was like a snake. The second who felt the elephant's

side said it was like a wall, while the third said it was like a spear as he touched the animal's tusk. The fourth,

who got hold of the elephant's tail insisted that it was like a rope. The fifth man said it looked like a tree as he

put his arms around one of the elephant's legs. The sixth, who was tall and got hold of the elephant's ears,

said it was like a huge fan.

     Each man's idea of the animal came from his own experience. So if someone disagrees with you about a

"simple fact", it's often because his experience in the matter is different from yours.

     To see how hard it is for even one person to make up his mind about a "simple fact", try this simple

experiment. Get three large bowls. Put ice water in one. Put hot water in the second. Put lukewarm water in

the third. Now put your left hand in the ice water. Put your right hand in the hot water. After thirty seconds,

put both hands in the lukewarm water. Your right hand will tell you the water is cold. Your left hand will tell

you it's hot!

1. What makes people think about simple facts differently?

A. The fact that simple facts differ from one another.

B. The fact that people have different experience in the same simple fact.

C. The fact that people often disagree with one another.

D. The fact that it's hard to make up one's mind about simple facts.

2. Which of the following temperatures can the word "lukewarm"be applied to?

A. Around 1℃

B. Above 60℃

C. Around 25℃

D. Below 0℃

3. After reading the last paragraph, we may think of _____.

A. Newton's law

B. Galileo's theory of falling objects

C. Einstein's theory of relativity

D. Marx's On Capital

4. The main idea of this passage is _____.

A. people often judge something according to his own experience

B. people often agree about simple facts

C. it's hard for a person to make up his mind about a simple fact

D. don't care too much about simple facts