vi.　主持，主管　be in charge of; lead

　～ at〔over〕　主持，负责

 ♣ preside at　(v.+prep.)
主持（会议、仪式等）lead; be president of a ceremony or meeting, etc.
　The minister was asked to preside at the independence ceremonies of the small island state.　那位部长被邀请去主持这个小岛国的独立仪式。
 ♣ preside over　(v.+prep.)
1.主持（会议、仪式等）lead; be president of a ceremony or meeting, etc.
　At the moment it is being presided over by each member in turn.　那时，每个成员轮流主持。
2.管理；对（某事物）负有责任control or be responsible for sth
　He presides over the company.　他管理这家公司。