搞不懂的一道GWD

lllmmm

Scientists claim that the discovery of the first authenticated mammal bones in amber could provide important clues *************
A.    of determining, in addition to how, when mammals colonized the islands of the West Indies
B.    in the determination of how and when the islands of the West Indies were colonized by mammals
C.    to determine how mammals colonized the islands of the West Indies and when they did
D.    for determining when the islands of the West Indies were colonized by mammals and how they were
E.    for determining how and when mammals colonized the islands of the West Indies
E肯定对  那A  B为什么不对呢

jasonhercules

先说A, in addition to how, 和 when, 没有平行对称，于是逻辑上就有重点when, 和非重点how。英语比较强调平行对称，所以错。另外，of determining, of也错误。
再说B, how和when倒是平行对称了，但后面采用了被动形式不如主动形式直接了当，不简洁，in the determination of就更不简洁了，用了一个这么复杂的短语。
最后是E, for determing 简单明了，how和when平行对称，加上主动形式，perfect.