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Zidovudine prevents human immunodeficiency virus mother to child vertical transmission;

齐多呋啶阻断艾滋病病毒母婴垂直传播

Construction of mouse model of vertical transmission by oral infection of Toxoplasma gondii;

经口感染弓形虫垂直传播小鼠模型的建立

Establishing mouse model of vertical transmission of Toxoplasma gondii;

弓形虫垂直传播小鼠动物模型的建立

A convenient method in solving the spiral perpendicular to the extruded object;

一种便捷的解决螺旋线与拉伸对象垂直的方法

By taking the strategy of uniting geometry with algebra and using the method of minimal value, the relationships of intersection, parallels and perpendicular between two three dimensional spaces in four-dimensional descriptive geometry are investigated and the calculation formula of the distance between two three-dimensional spaces are given.

用形数结合的观点和条件极值法，研究了四维空间的两三维空间的相交、平行和垂直的相互关系计算出两平行三维空间的距离。

By taking the strategy of uniting geometry with algebra and utilizing the principle that the dot product of two perpendicular lines is zero, all the perpendicular problems encountered in four-dimensional space are systematically discussed.

本文用形、数结合的观点,以两线垂直数性积为零作为基础,直线与三维空间垂直的投影特征作为图解问题的依据,系统地论述了四维空间里的所有垂直问题,且各种情况均有明确的结论。