know(or learn)from experience;realize 這方面他們是深有～的。They knew this very well./談?wù)勎覀€(gè)人的～。I’ll say a few words about my personal experience(or understanding)./你參加了這次討論會(huì)，有什么～？What do you think of the symposium?/你最近的出訪有何～？What have you learnt from your recent visit?/深有～ have an intimate knowledge of sth