祖始
词典originally：本；起初，原来；独创地，独出心裁地；自来。
词典祖始的解释
词典at the outset：当初；一开始。
1. 干细胞是细胞最先的祖始，有向各种细胞分化的能力。 Stem cells are the earliest precursors to cells; they have the potential to develop into a variety of different kinds of cells.