OG12 14求助 有关于状语从句省略的问题

引夕

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 appear on the surface of the Sun as dark spots although never sighted at
illustration for C:although typically introduces a subordinate clause, which has a subject and a verb, but here there is no subject and sighted is not a complete verb.
那为什么这里不能看成是状语从句的省略呢？
看到说状语从句的省略要求一是谓语动词是be，二是逻辑主语是句子主语。那我觉得这里两点都符合呀？
翻了之前的一些帖子也没明白……求教……

nemiah

应该用被动，不能省略

引夕

那就是说被动的情况下就不能省略咯？

gmatbiguo

在gmat中，although 必须引导从句，是从句就必须有主+谓的结构，该用法同以because /as引导的从句

引夕

我看新东方的那个OG题目解释里写“although引导的是完整句子，但要注意状语省略的情况”然后就是不太明白什么时候会发生状语省略的情况…………这题里的C为什么不能理解成这种情况？

qiuhua01234567

省略情况一个是主语是it或和主句主语相同，且在谓语中含有be，省略从句的主语和be，这里是被动啊，省略了be 就感觉意思出错了，容易混淆，我个人感觉是这样。

nemiah

我觉得这里应该不上have never been， 否则 sighted有修饰dark spots的嫌疑吧。。

sunsgiant

原句用连词but连接are visible as dark spots on the surface of the Sun 和 have never been sighted on the Sun's poles or equator.  说明这是并列关系，是两个平行独立的句子。改成although+状语从句就把两个句子的关系改为主从关系。这属于改变句子的重心~~~~

deityc

LS正解，我觉主要问题不是后面是不是句子的问题，而是重心变了

deityc

刚说完，就看到个反例.....

The Iroquois were primarily planters, but
supplementing their cultivation of maize, squash,
and beans with fishing and hunting.
(A) but supplementing
(B) and had supplemented
(C) and even though they supplemented
(D) although they supplemented
(E) but with supplementing

Key D