第1个回答 2008-06-18
master (mastering, has mastered in) the professional knowledge.
第2个回答 2008-06-18
master professional knowledge本回答被提问者采纳
第3个回答 2008-06-18
to master professional knowledge
第4个回答 2008-06-18
master the professional knowledge
第5个回答 2008-06-18
Master professional knowledge