Growth factors can act on many kinds of cells as mitotic promoter and deprival of growth factors can cause cease of cell growth or cell death . thus growth factors are usually thought relative to cell growth and differentiation 生长因子可以作为促分裂剂作用于多种细胞，剥夺生长因子可以导致细胞生长停止或细胞死亡，因此通常认为生长因子与促进细胞的增殖和存活有关。
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But the real urbanization in human society should be from the beginning of england industrial revolution in 1760s " . industrialization and urbanization were realized in england by using the primitive accumulation of the agriculture surplus and other industry workers " income of local deprival and overseas colonial loot 人类社会真正意义上的城市化应该从1760年代英国工业革命开始，英国通过在国内剥夺农业剩余和非农产业劳动者收入以及海外殖民掠夺完成原始资本积累，实现工业化和城市化。
