3.介词between和among的区别

　　解题要点 between表示二者之间，among表示三者或更多的整体概念。当A、B、C、D四项选择答案中出现between或者among时，它通常就是此题的命题焦点。

　　全真例题分析
（1） The determination of the path of Mars's orbit in 1609 became the unifying link among the two formerly separate realms of physics and astronomy.

(答案) C among改为between

（2） The Carlsbad caverns, located in New Mexico, rank between the largest underground labyrinths in the world.
(答案) B between改为among。表示多数概念，或范围时应用among。

（3） For a long time cotton ranked first bctween Alabama's crops, but today it accounts for only a fraction of the agricultural production.
(答案) A between改为among。表示范围时应用among。