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清晰的结构是DBMS具有______的一个必要条件。

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常用的模式分解的等价标准要求分解是具有______的和要求分解是保持函数依赖的。

There is no living creature that does not need sleep or completerest every day. If you want to know why, just try go without sleep for a long period 67. of time. You will discover that your mind and body would become tired 68. to work properly. You would find it hard to think clearly or concentrate in 69. your work. So sleep is quite simply the time when the cells of your bodyrecover from the work of the day and build up supplies of energy forthe latter period of activity. 70. One of the things we all know about sleep is that we areunconscious in sleep. We do not know what is going up around us. But 71. that doesn’t mean the body stops all activity. The important organs stop 72. to work during sleep, but most of the body functions are slowed down. For example, our breathing becomes quicker and deeper. The heart 73. beats more slowly, and the blood pressure is lower. Our arms and legsbecome limp (柔软的) and muscles are rest. It would be impossible for 74. our body to relax to such an extent if we were awake. So sleep does forus that the most quiet rest can not do. 75. And even though you are unconscious, many of your reflexes (习惯性思维) still work. For instance, if someone tickles (使……觉得痒)your foot, you will put them away in your sleep. You do this without 76. knowing it.

互联网的计算机是分布在不同地理位置的多台______的“自治计算机”。

Sam Gridley, a boy in his teens, ran away from his family’s crowded flat in New York. He went to the wild Catskill Mountain to live (47) himself. He lived there for almost a year before he was discovered by the (48) world. Here is part of his diary. I left New York in May. I had some necessary tools and $40. At about four o’clock, a truck driver and I passed (49) a beautiful dark forest, and I said to him, "This is as far as I’m going." The driver looked around and said, "Do you live here" "No," I said, "But I’m running away from home, and this is just the kind of forest I’ve always (50) about. I think I’ll camp here tonight." I jumped down. "Hey, boy," the driver shouted. "Are you (51) " "Sure," I said. "Well, isn’t that strange" he said. "When I was at your (52) , I did the same thing. Only thing was, I was a farm boy and ran to the (53) , and you’re a city boy running to the woods. I was scared of the city -- and will you be (54) of the woods" "Oh, no!" I shouted loudly. He laughed. Everybody laughed at me, even Dad, who once told me about the time he ran away from home. He got on a boat (55) Singapore, but when the whistle blew for departure, he ran down and was home in bed (56) anyone knew it.A) cityI) outsideB) afterJ) ageC) before K) forD) into L) scaredE) by M)throughF) dreamed N) oldG) from O) seriousH) hoped