I believe that species come to be tolerably well-defined objects . 我相信物种终究是界限分明的实物。
2.
They do not have a nuclear membrane and so no discrete nucleus . 原核体细胞没有核膜，因此也没有界限分明的细胞核。
3.
Only when both phases are present in the system is there a clear-cut distinction between liquid and gaseous states . 只有当体系中两相都存在时，在液体和气体之间才有界限分明的界面。
4.
Histopathological examination revealed a well - circumscribed dermal lesion of grouped cystic nodule developing from the infundibula of a ruptured follicle 病理检查显示在真皮及真皮下可见从一个破裂皮囊的漏斗部长出一群界限分明的囊状结节。
