off-diagonal的用法和样例：
例句
- The book has a diagonal black stripe on the cover.
书的封面上有条连接对角的黑斜线。 - Fill the rectangle with diagonal lines.
用对角线填充矩形。 - Draw a diagonal line to divide the square into two triangle.
画一条对角线，把正方形分成两个三角形。
词汇搭配
- off diagonal 非对角线的
- off diagonal element 非对角线元素...
