growth substance的用法和样例：
例句
- You should spread some growth hormone on the crops.
你应该给这些庄稼施一些生长素。 - The foreskin cells are grown on substrates, resulting in layered matrices that secrete growth factors.
因为包皮细胞可在培养基上继续生长，形成层层的基层，并能分泌出生长素。 - Hence, the biological grow-helping and the fast-growth and high-yield power have a substance foundation in improving the ability of frost-resistant of the seedings.
因此，生物助长剂和速生丰产灵等化控物质具有提高苗木抗寒性的物质基础的作用。
