The task demands special knowledge.

这项任务要求专业知识。

Do I need to have special knowledge or experience?

我需要具备特殊的知识和经验吗？

A foreign coach has special knowledge and expertise.

外国教练具有专门的知识和专长。

A person who has special knowledge or experience; an expert.

专家，内行有特殊或经验的人；专家。

He resolved to diffuse the special knowledge that he possessed.

他决心要传播他所具有的特别的知识。