【判断题】All of the projections of the intersection of a plane and a sphere are circles.
【判断题】If a line is an oblique line, the projections of the line will be foreshortened lines in the three planes of projections.
【简答题】以下函数是基本初等函数的有( )A. B. C. D.
【判断题】The projections of a groove in a cylinder are always visible.
【简答题】In the three projection system,what are callled the projections of a point respectively? 在三投影面体系中,点的投影分别为 、 和 。
【判断题】中国抗日战争胜利的根本原因是美国在日本投下了原子弹。( )
【判断题】中国抗日战争胜利的根本原因是美国在日本投下了原子弹。
【判断题】If a pont on a line in space, the projections of that point also lie on the corresponding projections of the line