单项选择题 Ink-jet printer belongs to nonimpact printers in which the characters are formed by projecting particles or droplets of ink on to paper.(71) printer is also a nonimpact printer in which the characters are produced by applying hot elements to heat-sensitive paper directly or by melting ink from a(72) on to plain paper. Electrostatic printer creates an electrostatic latent image, which is then made visible by a toner and transferred and fixed on paper. An electrostatic printer may be used in some instances as a(73). Laser printer creates, by means of a laser beam directed on a(74) surface, a latent image which is then made visible by a toner and transferred and fixed on paper. Magnetographic printer creates, by means of magnetic heads operating on a metallic drum, a latent image which is then made visible by a toner and transferred and fixed on paper. Computer-output-microfilm (COM) printer produces on a photographic film a(75) of each page.
单项选择题 表示关系x≥y≥z应使用C语言表达式()A.(x>=y)&&(y>=z)B.(x>y)AND(y>z)C.x>=y>=zD.(x>=y)&a
单项选择题 对于一个小型的软件开发项目,一个人就可以完成需求分析、设计、编码和测试工作。但随着软件项目规模的增大,需要有多人共同参与同一软件项目的工作。当几个人共同承担软件开发项目中的某一任务时,人与人之间必须通过交流来解决各自承担任务之间的(20)问题,即通信问题。通信需花费时间和代价,会引起软件错误(21),(22)软件生产率。如果一个软件开发小组有n人,每两个人之间都需要通信,则共有(23)条通信路径。假设一个人单独开发软件,生产率是5000行/人年,且在每条通信路径上耗费的工作量是250行/人年。若4个人组成一个小组共同开发软件,则小组中每个人的软件生产率为(24)。若小组有6名成员,则小组中每个成员的软件生产率为(25)。因此,有人提出,软件开发小组的规模不能太大,人数不能太多,一般在(26)人左右为宜。
单项选择题 通常采用白盒测试,(36)被称为组装测试。
单项选择题 在常见的页面置换算法中,(29)选择暂时不使用的或者在最长时间内不再被访问的页面作为被淘汰的页面,(30)总是选择淘汰最先进入内存的页面,而(31)选择淘汰在最近一段时间内最久未用的页面。在一个请求分页系统中,假如系统分配给一个作业的物理块数为3,并且此作业的页面走向为3,4,3,2,1,3,5,1,4,3,1,3,则采用FIFO和LRU算法的缺页次数分别是(32),(33)。