30日考试，什么都不会，请各位帮忙---Question 1

有两道题og 11th上面的

134 recently implemented shif-work equations based on studies of thje human sleep cycle have reduced sickness, sleeping on the job,and fatique among shift workers while rasing production efficiency.(正确答案，其他选项我就不打了）

9Sunpots， vortices of gas associtated with strong electromagnetic acitvity, are viisible as dark spots on the surface of the sun but have never been sighted on the sun's poles or equator.

我想问为什么but后面不用having never been呢？不是连词后面都用doing的表达的（好像是叫什么状语从句的），还是说but不是连词？

谢谢哪位老板教教我，我什么都不会，礼拜一就考了！！谢谢

补cong一点

9,有个选项 （D)appear as dark spots on the surface of the sun,although never having been sighted at

答案个选项为什么错的解释是although usually6 introduces a sbordinate clause, but here is no subject of the clause and having been sighted is not a complete verb phrase

照他们解释那while rasing不也错？？

大牛起床了吗？

大牛们，帮帮忙亚！！！！！！！！！！！

大牛没起床，偶醒着呢。。。

不好意思。。。 刚才按了一下回车。。。

连词后面未必加doing, 除非表示从句动词和主句动词同时发生，且从句主语和主句主语相同。 建议兄弟看看置顶的OG讨论。花三天把所有的过一遍，应该语法可以做到>70%