在软件开发过程中常用图作为描述工具。DFD就是面向 (19) 分析方法的描述工具。在一套分层DFD中,如果某一张图中有N个加工(process),则这张图允许有 (20) 张子图。在一张DFD图中,任意两个加工之间 (21) 。在画分层DFD时,应注意保持 (22) 之间平衡。DFD中从系统的输入流到系统的输出流的一连串连续变变换形成一种信息交流,这种信息流可分为 (23) 两大类。
A. 有且仅有一条数据流
B. 至少有一条数据流
C. 可以有0或多条名字互不相同的数据流
D. 可以有0或多条数据流,但允许其中有若干条名字相同的数据流
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Shell排序、快速排序、堆排序的稳定性如何 (58) 。若要尽可能的完成对实数数组的排序,且要求排序是稳定的,则应选 (59) 。若用插入排序算法对n个记录进行排序,最佳情况下,对关键字进行的比较次数为 (60) 。对于多关键字而言, (61) 是一种方便而又高效的文件组织方式。若用冒泡排序对关键字序列19,16,11,8,5,3从小到大进行排序,则需要次数为 (62) 。 58()
A. Shell排序是稳定的
B. 快速排序是稳定的
C. 堆排序是稳定的
D. 都不稳定
视频卡的种类很多,主要包括 (7) 。以PAL制25帧/秒为例,已知一帧彩色静态图像(RGB)的分辨率为256×256,每一种颜色用16bit表示,则该视频每秒钟的数据量为 (8) 。全电视信号主要由 (9) 组成。在视频信号实时处理技术中,如果电视扫描的正程时间为52.2ms,分辨率为512×512,实时意味着处理每个像素的时间近似为 (10) 。 10()
A. 0.1ms
B. 0.2ms
C. 0.8ms
D. 0.4ms
数据链路层中的数据块常被称作()。
A. 信息
B. 分组
C. 帧
D. 比特流
阅读下面的短文,文中有15处空白,每处空白给出4个选项,请根据短文的内容从4个选项中选择1个最佳答案。 A satisfactory psychological theory must allow us to predict behavior. For instance, a satisfactory theory of hunger will allow us to predict when people will eat and not eat. A broadly satisfying, (51) theory should have a wide range of applicability. A broad theory of hunger might apply (52) human beings and lower animals, to normal weight and overweight people, and to people who have (53) of food for differing lengths of time. If our (54) cannot be adequately explained by or predicted from a given theory, we should consider revising or replacing that theory. In psychology many theories have been found to be (55) of explaining or predicting new observations. As a result they have been revised (56) .For example, the theory that hunger results from stomach contractions may be (57) correct for normal weight individuals, but it is inadequate as an (58) for feelings of hunger among the overweight. (59) theories also focus on biological variables, such as fat cells and brain (60) , and psychological variables such as the presence of other people who are eating and the time of day. The (61) of controlling behavior in psychology is highly (62) . Some people erroneously think that psychologists seek ways to make people do their bidding—like puppets dangling on strings. This is not so. Instead, psychologists help (63) change their behavior for their own benefit. Psychologists are (64) to belief in the dignity of human beings, and human dignity demands that people be free to make their own decisions and choose their own behavior. Psychologists are learning more all the time about the (65) influences on human behavior, but they apply this knowledge only upon request and in ways they believe will be helpful to an individual or an institution.
A. clients
B. customers
C. consumers
D. users