To choose not to participate in something
決定不參加某組織，脫離
“give individual schools the right to opt out of the local educational authority”(&b{Newsweek})
“給予每一學(xué)校有脫離地方教育行政體系的權(quán)利”(&b{新聞周刊})
choose to participate
決定參加
the database would not include a person's name unless he opted in.
除非決定參加，否則數(shù)據(jù)庫將不錄入姓名。
choose not to participate in or carry on with something
決定不參加；退出
the treaty gives any country the right to &B{opt out of} a single currency.
條約賦予任何國家退出單一貨幣的權(quán)利。