allowing them to grow bigger and stronger than ever before. 使植物能够生长得比以往任何时候 都更大、更强壮

39. Key was the evolution of a new compound,
    其关键是一种新化合物的进化
40. lignin.
    木质素
41. Lignin strengthened the plants' cell walls...
    木质素加强了植物的细胞壁
42. allowing them to grow bigger and stronger than ever before.
    使植物能够生长得比以往任何时候 都更大、更强壮
43. No longer confined to carpeting the land,
    不再局限于覆盖地面
44. plants began to battle for the real estate above,
    植物开始争夺向上的空间
45. fighting for access to light.
    以获取阳光

来自《我们星球上的生命 第一季 第三集 Life on Our Planet S01E03 入侵大地》第 42 行