preside at(v.+prep.)
主持(会议、仪式等)lead; be president of a ceremony or meeting, etc.
▲preside at sth
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。
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preside over(v.+prep.)
▲preside over sth
1.主持(会议、仪式等)lead; be president of a ceremony or meeting, etc.
◇ 用于be ～ed结构
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。