利用3×3矩阵进行二维点集变化时,我们使用的矩阵为[1,0,0;0,-1,0;0,0

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问题:

利用3×3矩阵进行二维点集变化时,我们使用的矩阵为[1,0,0;0,-1,0;0,0,1],那么变化后的效果为()

A.沿着X轴对称变换

B.沿着Y轴对称变换

C.沿着原点对称变换

D.沿着直线y=x对称变换

考点:艺术设计软件3DMAX3DMAX题库
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种子的胚乳或子叶中贮藏有大量的营养物质,主要是淀粉、蛋白质和脂肪,它属于()组织,我们食用的粮食和油料主要来自种子些部分。

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丝杆和螺母之间的相对运动属于()。

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People today all over the world are beginning to hear and learn more and more about the problem of pollution. (46) Pollution is caused by either the release by man of completely new and often artificial substances into the environment, or by releasing greatly increased amounts of a natural substance, such as oil from oil tankers into the sea.
(47)The whole industrial process which makes many of the goods and machines we need and use in our daily lives, is bound to create a number of waste products which upset the environmental balance, or the ecological balance as it is also known. (48) Many of these waste products can be prevented or disposed of sensibly, but clearly while more and more new goods are produced and made complex, there will be new, dangerous wastes to be disposed of, for example, the waste products from nuclear power stations.
(49)Whatever its underlying reasons, there is no doubt that much of the pollution caused could be controlled if only companies, individuals and governments would make more efforts. In the home there is an obvious need to control litter and waste. Food comes wrapped up three or four times in packages that all have to be disposed of; drinks are increasingly sold in bottles or tins which cannot be reused. This not only causes a litter problem, but also is a great waste of resources, in terms of glass, metals and paper. Advertising helped this process by persuading many of us not only to buy things we neither want nor need, but also to throw away much of what we do buy. (50)Pollution and waste combine to be a problem every one can help to solve by cutting out unnecessary buying, excess consumption and careless disposal of the products we use in our daily lives.

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造成涎瘘的主要原因是

A.面颊部损伤

B.涎腺肿瘤

C.面颊部放疗

D.涎腺化脓性感染

E.先天性发育不全

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《禁毒法》规定,国家机关、社会团体、企业事业单位以及其他组织和公民,应当履行()职责或者义务。

A、学习贯彻的

B、遵守本法条款的

C、禁毒宣传

D、禁毒

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