among 与 between

介词 among 与 between 的用法类似，而且表达的意思几乎相同，但两者之间仍存在重要差异； 该差异可通过以下例句说明。

Between
Between 用于表达涉及两件事物的关系：

1. A reaction between two unstable compounds resulted in an explosion.

Among
Among 用于表达涉及三件或更多事物的关系：

2. The separation of sequences among DNA fragments was done using gel electrophoresis.

[1] 这类词语也可当作副词使用，不过我们在此不讨论这样的用法。