对应后面的who，the Oneida指the Oneida people，是复数名词。
alone adj或adv，C中alone作副词，the Oneida sided alone with the colonists during the American Revolution among the five-nation Iroquois League.
league联盟，是单数，不能说the only one of +单数名词，不能说the only oneS

A项主句为系表结构， influence状语从句不应该修饰系表结构，而应该修饰side

side with 与...站在一起
其实化简一下就是 the Oneida alone sided with the colonists during the American Revolution.
among the five nations of the Iroquois League是状语
1. "five-nation" is actually an adjective. So, the five-nation Iroquois League is a singular noun phrase. We cannot say "one of/ alone of/ only of / the five-nation Iroquois League". i.e. these constructions seem like "one of apple/ alone of apple / only of apple". So, we can kill A, B and E.
D. Only与ones前后单复数不一致。

A the oneida 代表一类人群，复数； five-nation Iroquois League是一个单数名词，不能说one of+单数名词
D ones歧义，可能表示不是来自一个nation

MARK

i will admit that this is a problem that is brutal to non-native speakers of the english language. but, in this problem, "the oneida" functions identically to constructions such as "the french" or "the english", which are also uniformly plural.

原句句子结构：…, the Oneida… sided with….
原句逻辑语义：极大地受到新教传教士塞缪尔·柯克兰的影响，奥奈达市是易洛魁五国联盟中唯一一个与殖民者站在同一阵营的，在美国革命期间。

A. The Oneida为集合名词，谓语应为复数were。
B. The Oneida为集合名词，谓语应为复数were。
C.正确。
D. Only与ones前后单复数不一致。
E.使用过去完成时没有根据，本句为对过去事件的简单描述，不够成“过去的过去”这一时点，所以不应该使用过去完成时。

B：they指代不清

ABE都说的是 league5国成员side with，不合逻辑，side的主语应该是Oneida

(pl. Oneida,Oneidas) 奥奈达人（美国纽约州、威斯康星州的印第安人）
protestant新教教徒 missionary传教士

1.the+一类人 pl 排除AB

2.the only one of the five-nation Iroquois League即the only one of League，the only one of+n复才对，表示许多N中的一个，这里league单数，错，同理onlyof，alone of-----排除ABE

3.D:the only 表示唯一的，ones表示复数 矛盾，Oneida是one不是ones

4.E：过去完成时 没必要

5.C：正确 the Oneida主语 （alone 相当于only强调唯一 among the five nationsN复正确 of the Iroquois League） sided谓语 with...

3. in Choice D, "ones" groundlessly assumes that the Oneida consist of more than one nations and, in turn, changes the meaning.

2. in Choice B, "they" has no clear referent, because "was" already signifies "the Oneida" as a singular noun that is not consistent with "they", and because "Iroquois" actually acts as an adjective(Pronoun can only refer noun and noun phrase).

1. "five-nation" is actually an adjective. So, the five-nation Iroquois League is a singular noun phrase. We cannot say "one of/ alone of/ only of / the five-nation Iroquois League". i.e. these constructions seem like "one of apple/ alone of apple / only of apple". So, we can kill A, B and E.

此题需先弄清楚主句的谓语动词，从整个句子的逻辑意思可以看出整个句子的意思是“被...影响了，Oneida和colonists站在同一战线”。可见，位于动词是side with。由此排除A/B/D；而C和E选项，很容易便可分析出E选项是错误的选项。

(A) was the only one of the five-nation Iroquois League who sided ----one of somethings 后面something必须是复数，但是后面的five-nation Iroquois League 是单数，是一个联盟，所以是不对的

side with谓语，表示支持

A错是因为有歧义吧

A：1) For somebody who doesn't know about Oneida would take it as a league/ some association/nation and hence singular. In that case, 'was' would be correct and 'who' would be incorrect.
2) If I know that "the Oneida" refers to an entire tribe / group / race and hence plural, then 'was' would be incorrect and 'who' would be correct.