关于补体的正确叙述是（）。

A.是一组具有酶促反应活性的脂类物质

B.主要由活化的淋巴细胞产生

C.参与免疫病理反应

D.对热稳定

E.血清中C1含量最高

Requirements management is the process of （）, analyzing, tracing, prioritizing and agreeing on requirements and then controlling changes and com municating to relevant stakeholders.

A.communicating

B.collecting

C.filing

D.documenting