问一个幼稚但让我不舒服的问题: 9.Sunspots, vortices of gas associated with strong electromagnetic activity, are visible as dark spots on 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 (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 darkspots 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 这道题选A,没问题,问题是although的省略使用,主要集中在C和D选项。 我找了很多帖子,总结下来就是说当主从句主语一致,从句是主系表结构时,although后省略相同主语,接doing/done,那我就奇怪了,主系表结构省略be以后doing是哪个do的现在分词呢?还有C选项sighted就是done嘛,本身应该有被动的意思了呀? 觉得明知道语法但套不进题来使用的感觉很差  |