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因争用资源产生死锁的必要条件是互斥、循环等待、不可抢占和 (16) 。对于缓冲池 (大量缓冲区)的管理，采用生产者-消费者方式解决同步或互斥时，通常需要用 (17) 个信号量。 （17）处填（）。
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A huge population of red fire ants has bedeviled Texas farmers for years. By some estimates the insectscost state businesses close to $1 billion a year due to crop and machinery destruction. Killing the ants and their nests has not proven easy. Texas A＆M researchers have discovered that the phorid fly from South America will lay eggs on the red fire ants and the maggots which are hatched eat away at the ant’s brains, eventually causing their heads to fall off. Someone at the university was willing to underwrite the work to solve a problem. That investment was almost certainly much less than the $1 billion a year that fire ants cost businesses in the state. A recession does not stop advancements in technology. It just makes companies so frightened of risk that they choose not to make the investment in the red fire ant projects. In the last week, the two most successful technology companies in the world, IBM and Google have announced major new products. IBM released "stream computing" applications that allow businesses to look at and analyze huge amounts of data in real time. The most important product of Google allows the company’s customers to take very large amounts of search data and organize it into spreadsheets. These are developments that will probably help the firms take business away from their competitors. The shares of Google and IBM have handily outperformed those of all the other large tech companies based in the U. S. such as Hewlett Packard (HPQ), Microsoft (MSFT), Cisco (CSCO), and Oracle (ORCL). Each of the companies is blessed with substantial earnings and technology staffs in the tens of thousands. But the firms are not all viewed the same, at least by investors who trade tens of millions of their shares each day. In most ways, IBM and Google are not like one another at all. IBM makes its money selling expensive hardware, client services, and software to companies, most of which are very large, and to governments. Google has millions of customers who pay nothing to use its services. It has millions of advertisers who spend money to reach people who look at search results and most of these marketers are very small. What the companies do have in common is a willingness to take risks, probably risks with long odds in order to launch new products. These products may be failures, but they are well enough researched and designed that they have a good chance of keeping IBM and Google ahead of the competition even if that does not immediately involve significant new revenue. The red fire ant problem never goes away. Unsolved problems in every industry cost companies money. Sometimes companies do not even know that their problems can be solved. The phorid fly is an obscure species. So is software that can analyze huge amounts of data in real time. It is implied that Hewlett Packard and other big companies
请根据以下资料。回答下列问题。 某项目施工现场设有混凝土搅拌站，为了赶工期，施工单位实行“三班倒”连续进行混凝土搅拌生产。附近居民意见极大，纷纷到有关管理单位反映此事，有关部门也作出了罚款等相应的处理决定。 环境管理体系运行过程中对有关的人员培训的内容包括______。
虚拟存储管理系统的基础是程序的 (25) 理论，这个理论的基本含义是指程序执行时往往会不均匀地访问主存储器单元。根据此理论，Denning提出了工作集理论。工作集是进程运行时被频繁地访问的页面集合。在进程运行时，如果它的工作集页面都在 (26) 内，能够使该进程有效地运行，否则会出现频繁的页面调儿调出现象。 （25）处填（）。
在有一台处理机CPU和两台输入/输出设备I/O1和I/O2，且能够实现抢先式多任务并行工作的多道程序内，投入运行优先级由高到低的P1，P2，P3三个作业。它们使用设备的先后顺序和占用设备时间分别是：作业P1：I/O2(30毫秒) CPU(10毫秒) I/O1(30毫秒) CPU(10毫秒)作业P2：I/O1(20毫秒) CPU(20毫秒) I/O2(40毫秒)作业P3：CPU(30毫秒) I/O1(20毫秒)在对于其他辅助操作时间可以忽略不计的假设下，作业P1，P2，P3从投入到完成所用的时间分别是 (39) 毫秒， (40) 毫秒和 (41) 毫秒。三个作业从投入运行到全部完成，CPU的利用率约为 (42) %，：U01的利用率约为 (43) %。假定在系统中仅有这三个作业投入运行，各设备的利用率指该设备的使用时间同作业进程全部完成所占用最长时间的比率。 （42）处填（）。
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