Even on an erased hard drive there are residual artifacts. 即便是删除过的硬碟，里面总还有残存的痕迹。
Because the frozen sections revealed no residual tumor cell after tumor excision, canaliculostomy and semicircular flap was performed simultaneously. 病人在接受肿瘤切除送冷冻切片证实没有残存癌细胞后，接受泪小管造口手术及眼睑半圆形皮瓣重建。
