如果两个正交坐标轴之一为图形的对称轴,则这对坐标轴肯定是图形的主惯性轴。
查看答案
平面图形对包含主轴的直角坐标系的惯性积一定等于零。
A. 对
B. 错
His visit is direct evidence of the (improve) in their relationship
I have always believed that a garden dies with its (create).
It is necessary to get the youth to have a high (enthics) concept.
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