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问题 单项选择题

在一个单CPU的计算机系统中，采用可剥夺式(也称抢占式)优先级的进程调度方案，且所有任务可以并行使用I/O设备。下表列出了三个任务T1、T2、T3的优先级、独立运行时占用CPU和I/O设备的时间。如果操作系统的开销忽略不计，这三个任务从同时启动到全部结束的总时间为 (15) ms。CPU的空闲时间共有 (16) ms。

表13-1 任务优先级及占用设备时间情况表
任 务 优先级 每个任务独立运行时所需的时间
T1 高 对每个任务：占用CPU 10ms，I/O 13ms，再占用CPU 5ms
T2 由
T3 低

A．28

B．58

C．61

D．64

答案

参考答案：B

填空题

Perhaps, every county suffered from inflation once or more times. Inflation is an economic condition in (B1) prices for consumer goods (B2) , and the (B3) of money or purchasing power decreases. There are three causes of inflation. The first and most important cause may be excessive government spending. For example, in order to (B4) a war or carry (B5) social programs, the government may spend more money than it has received through taxes and other revenues, thus creating a deficit. In order to (B6) this deficit, the Treasury Department can simply (B7) the money supply by issuing more paper money to (B8) the debts of government. This increase in the money supply will cause the value of the dollar to (B9) decrease. The second cause of inflation occurs when the money supply increases faster than the supply of goods. (B10) people have more money, they will run out to buy popular goods (B11) televisions and computers, for example, and a shortage will result. Industry will then produce more, at higher prices, to (B12) demand. (B13) , if people think that the prices of popular goods are going up, they will buy and even borrow money at high (B14) rates to pay for them. Finally, if labor unions demand that workers’ wages (B15) or (B16) the high cost of living, industry will meet this demand and add other costs of production on the (B17) . (B18) summary, all of these causes can (B19) inflationary problems that can affect the welfare of a nation. However, of these three causes, (B20) government spending may be the most important.

A．However

B．Otherwise

C．Nevertheless

D．Furthermore
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单项选择题

骨折体征中下列哪项是错误的

A．疼痛、肿胀

B．反常活动

C．畸形

D．弹性固定

E．骨擦音
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