stalk line

• 对称

stalk line的用法和样例：

例句

1. A kite is a quadrilateral with one line of symmetry.
   风筝是个有一条对称线的四边形。
2. Can you get a perfectly symmetrical pattern if you put a mirror on the dotted line?
   如果在虚线上放一面镜子，你能得到一个完整的对称图案吗？