定界线

例句：

1. 1. The artist carefully delineated the outline of the painting on thecanvas.
   艺术家仔细地在画布上勾勒出这幅画的轮廓。
2. 2. The teacherdelineated the key points in thelesson plan.
   老师在课计划中明确了重点。
3. 3.The scientist delineated the boundaries betweendifferent species.
   科学家界定了不同物种之间的界限。