specialist和expert有什么区别?

specialist和expert有什么区别? specialist 和expert有什么区别? specialist和expert的区别? specialist和expert的区别? expert和specialist的区别 请问 savvy expert specialist 的区别和用法. training officer和training specialist有什么区别? staff/specialist/executive/有什么区别? an expert in/at/on/with有什么区别?例子：1.an expert in/at teaching small children意思就是说an expert in和an expert at通用对吗?2.an expert in economics3.an expert on foreign affairs4.an expert with the needles a specialist or an expert in genetics（a noun） expert at/on/in 有什么区别 specialist什么意思 Logistic Specialist什么意思 expert用法expert后面带介词in,at,on,有什么区别啊? an expert in/on/at有什么区别 expert什么意思 expert什么意思 expert什么意思