【求助】OG里的问题

霸王椰子

OG 15版17题：Sunspots, vortices of gas associaed with strong electromagnetic activity, are visible as dark spots on the surface of the Sun but have never been sighted the Sun's poles or equator.
A are visible as dark spots on the surface of the Sun but have never been sighted on
B are visible as dark spots that never have been sighted on the surface of the Sun
C appear on the surface of the Sun as dark spots although never sighted at
D appear as dark spots on the surface of the Sun, although never having been sighted at
E appear as dark spots on the Sun's surface, which have never been sighted on
这道题答案是A，然后解析里明确支出although引导从句，从句中应该有完整的主语和谓语，所以CDE不能选。而矛盾出现在OG verble分册中的第36题：
Polio, although it is eradicated in the United States, it continues elsewhere and is able to be brought into the country by visitors.
B Polio, although eradicated in the United States, iit still continues elsewhere and can be
C Although still continuing elsewhere, Polio has been eradicated in the United Stated and could be
D Although having been eradicated in the United States, polio still continues elsewhere and is capable of being
E Although eradicated in the United States, polio continues elsewhere and could be
这道题答案选E，解析说没有语法错误，但是这个选项也是用although引导，但是没引导完整的句子，而是引导了一个分词，虽然这道题的确没有比这个更好的答案了，但是毕竟也是语法错误啊。
求大神解答这个矛盾怎么解释啊。跪求~~祝大家都过750~~

ukyo2003

Although 和Though在引导状语clause可以省略主谓，但是要求是1、逻辑主语=主句主语；2、Although引导的状语从句谓语是be动词；3、主语谓语同省同留

老李同志

这里主语一致，可以省略啦

霸王椰子

非常感谢！