expert
习惯用语be expert in ...1.■在...方面是专家be expert at ...1.■在...方面是专家特殊用法advertising expert1.■广告师associate expert1.■助理专家consultancy expert1.■咨询专家corrosion expert1.■防锈专家data processing expert1.■数据处理专家educational expert1.■教育专家legal expert1.■法律专家[鉴定人]resident expert1.■常驻专家