one of a number of things from which only one can be chosen
例句
用作名词 (n.)
For people who chose not to eat meat there are many alternatives. 对于那些决定不吃肉的人来说,还有很多其它选择。
They resisted the introduction of impractical alternatives. 他们抵制采取那个不切实际的备选方案。
It also includes a consideration of possible alternatives, such as a concrete gravity dam or an earth-fill embankment dam. 还要考虑到可能的备选方案,比如是选择混凝土重力坝还是选择填土筑堤大坝。