Session: a formal meeting or series of meetings of a court of law, a parliament, etc.; a period of time when such meetings are held （法庭的）开庭，开庭期；（议会等的）会议，会期
a session of the UN General Assembly
一届联合国大会
The court is now in session.
法庭现在正在开庭。
The committee met in closed session(= with nobody else present).
委员会举行了秘密会议。
Expertise: expert knowledge or skill in a particular subject, activity or job 专门知识；专门技能；专长
professional/scientific/technical expertise
专业／科学／技术知识
They have considerable expertise in dealing with oil spills.
他们在解决溢油问题方面非常在行。
We have the expertise to help you run your business.
我们有帮助你经营自己业务的专门知识。
Personnel: the people who work for an organization or one of the armed forces （组织或军队中的）全体人员,职员
skilled/trained personnel
熟练的／训练有素的人员
sales/technical/medical/security personnel
推销／技术／医务／保安人员
army/military personnel
陆军军事人员
