Why did one university give every one of its incoming freshmen a free Apple iPad?
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In what condition will a university be at a competitive disadvantage according to a university president?
Why are colleges around the world replacing their computer systems?
由一条母线(直线或曲线)围绕轴线回转形成的曲面,称为____。
回转面有一重要特性,母线上任意一点的回转运动轨迹是一个垂直于轴线的____。
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