求助一道语法题目

sinadragon

Q1: Sunspots, vortices of gas associated with strong eleconmagnetic 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 the

(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

which one is the correct anwser and why?

thanks

cross263

我看A最顺眼

realheart

同一楼上的，只有A的逻辑表达最合理

trifling

选c首先用at poles and equator,不用on

此外done 优于having been done

cross263

C 的sighted 前面少了系动词, Although 后面要跟完整的句子。至于at 还是 on,我觉得可能不是这道题的考点

creativity

“C 的sighted 前面少了系动词, Although 后面要跟完整的句子”

这个不是关键，而且是语法许可的。