哪个牛人来解答一下OG SC14 急！

zlljolie

牛人来看一道OG SC题 高人求解
14.Sunspots, vortices of gas associated with strong electromagnetic activity, are visible as dark spots on the surface of the Sun but have never been sighted on the sun's poles or equator.
A  are visible as dark spots on the surface of the Sun but have never been sighted on
C  appear on the surface of the Sun as dark spots although never sighted at
正确选项选A，OG解释说visible和sighted对应，C选项错在although后面应该跟句子，但是C中是短语sighted.

我觉得C也没错啊，状语从句不是有一种省略式吗，就是从句主语和主句主语一致，从句完整是although they have never been sighted at，这里省略了they have never been( sb be), they就是指sunspots。
牛人看看，这种想法不对吗？

啊孙

A 和 C 所表达的逻辑意思不同。
A 强调的but 后面的东西，sunspots have never been sighted on
C 强调前面的东西，are visible as dark spots on the surface （尽管XXXX)
我的理解

renco

appear跟are visiable是两个完全不同的概念。C选项的意思是黑子确实在表面出现只是没被看到而已，A选项说的是能在表面看到但是两极和赤道没看到过。也就是说C选项确认黑子随处可以出现，从逻辑上来说，这是不可能的。

ainiAnnie

从句意解题，although在表达contrary的意思上没有but好。
且 although后面应该加从句，有主语和谓语。
个人愚见。

ychen34

应该不可以省略be吧 前面半句的动词时appear 不是be动词啊

lminj

我只想问  at the sun's poles or equator./on the sun's poles or equator
at的用法对不对……？

oncedream

顶上去。。。。。。。正在做这道题。看不懂啊！！

renco

你纠结什么，你自己都知道A比C好，完毕。

GJane

同问，求解答，本身两个句子的主语不都是sunspots么？

jefferson911

我也在做哈，做了两遍下来的理解就是，OG里的Although表反转，都要跟完整的逻辑主语和动词组成完整的句子。
A：Sunspots（, vortices of gas associated with strong electromagnetic activity, ）are visible as dark spots on the surface of the Sun but have never been sighted on the sun's poles or equator.
C：Sunspots（, vortices of gas associated with strong electromagnetic activity, ）appear on the surface of the Sun as dark spots although （which were?） never sighted at the sun's poles or equator.
这样解释对不对呢……我是这么理解的~就是OG里的句子逻辑指代一定要完整……不对的话别见怪我也在学哈，希望能帮上忙

-- by 会员 gavin5878 (2011/9/20 22:48:23)

你的意思是把Sunspots理解为sighted at的主语么？这样一来，逻辑意思上不符合，OG说"there is no subject"；sighted一般过去时，时态上也不完整，OG才说“sighted is not a complete verb”。


省略的话，我查了一种解释说，although要放在句首，省略规则才适用，看有没有牛人指点一二？