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问题 填空题

完备的网络安全服务功能主要有：保密性、认证、数据完整性、防抵赖和______。

答案

参考答案：访问控制

解析： 一个功能完备的网络系统应该提供基本的安全服务功能：保密性、认证、数据完整性、防抵赖、访问控制等。

单项选择题 A1/A2型题

呕吐伴上腹部节律性、周期性痛可见于（）

A.慢性胆囊炎

B.消化性溃疡

C.肝硬化

D.急性胃炎

E.胆石症
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单项选择题

I got a job teaching special education at a school in Coachella, California, a desert town about 170 miles from home. It was no (1) job. Street gangs (2) around the school after dark."Be careful," Dad warned me during one of my frequent weekend (3) home. He was concerned about my living (4) , but I needed to be on my own.One evening, I stayed after school to rearrange my classroom. (5) , I turned out the light and closed the door. Then I (6) toward the gate. It was (7) ! I looked around. Everyone had gone home.After (8) all the exits, I found just enough (9) to squeeze under a gate in the back of the school. Then I walked toward my car, parked in a field behind the building.Suddenly I heard voices. I (10) around and saw at least eight boys following me. (11) my pace, I reached into my shoulder bag to get my key. I (12) all over the inside of my handbag. But the key wasn’t (13) ! Dear Lord, please help me, I prayed (14) . Suddenly, my fingers touched a loose key in my purse. I didn’t even know if it was for my car, but I took it out and (15) it. It worked!I opened the door, slid in and locked it—just (16) the teenagers surrounded the car. Trembling , I started the engine and (17) away. When I returned to my apartment, the phone was ringing. It was my Dad. I didn’t tell him about my experience; I didn’t want to (18) him. "Oh, I forgot to tell you!" He said, "I had a(n) (19) car key made and slipped it into your purse—just (20) you ever need it.

 

第（15）空应选择（）

A．pushed

B．turned

C．tried

D．opened
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