搜题请搜索小程序“爱下问搜题”
问题 问答题

在以M/M/1为模型的分组传输系统中，设λ=2（顾客/秒），μ=3（顾客/秒），求：

每一顾客在系统中的平均等待时间。

答案

参考答案：[*]C:\Documents and Settings\Administrator\My Documents\图片\6.jpg

单项选择题 案例分析题

患者，女，40岁，双下肢紫癜伴血尿3天，无发热、腹痛、黑便，1周前出现咽痛，体检：双下肢可见大小不等、对称分布的暗红色紫癜，按之不褪色，血小板计数150×109/L，尿常规示潜血（++），蛋白（++），凝血时间7分钟，血小板凝集功能正常，骨髓象正常

提问：患者最可能的诊断为（）。

A.免疫性血小板减少性紫癜

B.过敏性紫癜

C.单纯性紫癜

D.肾小球肾炎

E.遗传性出血性毛细血管扩张症
查看答案
完形填空

Enough sleep is important to health. The amount of sleep __1________(need) depends on the age of the person and the conditions in _2.________ sleep takes place. The young may need more sleep than __3.________ old, but usually eight hours are enough for the health of grown-ups. Some can do with ___4_______ than this amount, but others may need more. Every person knows his own need. ___5_______ is then a matter of good judgment to satisfy his need. Sleep should always be enough to make one bring back his __6.__________ (strong) and get ready for a day’s work.

Fresh air is necessary to sound sleep. So it is not __7.___________ reason for some people to think that it is practicable to sleep in the open air. A bath at bedtime, __8._________ hot nor cool but of body temperature, may be helpful_9._________ sleep. Sleep-producing drug should never be taken except when _10.________ (suggest) by a doctor.
查看答案