prep 3道SC

1，o-called green taxes, which exact a price for the use of polluting or nonrenewable fuels, are having a positive effect on the environmental and natural resource base of countries as varied as China, the Netherlands, and Hungary.
A as varied as
B as varied as are 
C as varied as those of 
D that are as varied as
E that are varied as are

OA是A，我选的C啊，我认为those指代the environmental and natural resource base 。然后the environmental and natural resource base of countries 和those of China平行。谁给解释一下？

2,Greatly influenced by the Protestant missionary Samuel Kirkland, the Oneida was the only one of the five-nation Iroquois League who sided with the colonist during the American Revolution.
A) was the only one of the five-nation Iroquois League who sided
B) was alone of the five-nation Iroquois League when they sided
C) alone among the five nations of the Iroquois League sided
D) were the only ones out of the five nations of the Iroquois League in siding
E) only of the five-nation Iroquois League had sided

OA是C，但是C我怎么看都觉得别扭，老是觉得lone前面应该加个was。谁能给分析一下

3,Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.
            
D) the horny jaws function as teeth do
E) the horny jaws function as teeth

D,E搞不清该选哪个，OA是E。

我比较疑问的是 为什么A回错，虽然C是没有错误的，但是C改变了语义重心阿

2,Greatly influenced by the Protestant missionary Samuel Kirkland, the Oneida was the only one of the five-nation Iroquois League who sided with the colonist during the American Revolution.

A) was the only one of the five-nation Iroquois League who sided