The two opposition parties made an electoral pact.那两个反对党订了一个有关选举的协定。
The two governments signed a pact that they would jointly defend their borders.两国政府签署了一项共同防守两国边界的条约。

pact, agreement, contract, treaty
这组词都可指“协定”。pact用来指国家、团体或个人之间的“协定”
treaty指在外交谈判后按国际公法签署的正式条约,在重要性和约束力上都比pact强; agreement泛指人与人之间、团体或国家之间达成的任何“合同,协定”,包括正式的或非正式的、书面的或口头上的; contract通常用于双方或多方订立的“契约”,为正式的,有法定效力。

［同义词］   agreement, contract, treaty