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设有关系模式R(U,F),其中 :属性集U为ABC,函数依赖集 F={A→BC,B→C,A→B,AB→C}( 1 ) 计算A+( 2 ) 求 F 的最小等价依赖集 Fmin

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1.A heavy flood caused the bridge to ; now, no one can cross the river without boats.2.Susan has been crying a lot since her sister died a year ago; it seems that she could never from the heavy loss.3.It's sometimes considered bad manners to on the table while eating, so please be careful not to do so.4.After crying for some time, she looked at her face in the mirror, only to find she was such a sad and plain-looking girl.5.I had to hold tightly the handrails (扶手) along the hall to keep myself from losing my balance on the floor.6. The man phoned the police and later went to the police station to look at photos to the robbers.7. The imperial examination system, which started in the Sui Dynasty, was in 1905.8. Many smokers choose to the fact that smoking is harmful to health and refuse to stop smoking.9. He no longer had a(n) for further education because he thought the costs were too high.10. Although she often seemed quite cold and strict, her smiling eyes her true nature.

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高程和DEM

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商业空间设计中，实体空间与虚拟空间的区别体现在以下哪些地方？

A. 设计时分割空间的方式不同，实体空间是绝对分割，而虚拟空间则是相对分割。
B. 划定空间的方式不同，实体空间是阻隔来划定空间，虚拟空间是需要联想和视觉完形性来划定空间。
C. 空间中人流交通动态线的特点不同，实体空间的人流交通动态线是清晰的，虚拟空间的人流交通动态线是模糊的。
D. 构成空间的方式不同，虚拟空间可以借助家具,陈设,绿化,水体,照明,色彩,材质,改变标高等来完成，而实体空间利用墙体等完成。

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在商业空间设计中，实体空间的设计具备哪些特点？

A. 在商业空间中实体空间包含了光、镜子、色彩等
B. 在商业空间中大部分实体空间多由实体的墙面围合而成
C. 在商业空间的水平限定上包含了地面、顶面、商品
D. 在商业空间的垂直限定上包含了墙面、柜台、家具、物品柜、植物

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