It is doubtful whether true linearism exists in any social process or evolution. 在作何社会演变过程或进化中是否存在着真正的直线连续性是个疑问。
The evolution of species presupposes a process of natural selection. 生物演变是以自然选则的过程为前提的。
Maignant melanoma of oral mucosa is a rare and disastrous disease, and it is much rarer to have neck metastasis. 摘要口腔黏膜的恶性黑色素瘤颇为少见,由于不易早期诊断,病程又极恶性,所以预后甚差。
Additionally, surgery prevents the possibility for developing colorectal malignancy, which increases with the duration of disease. 此外,手术阻止了结直肠恶变的可能性,并增加了病程。