OG 11 009 as 为什么后面直接接名词？

hanlei8492

1.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.
 (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
I chose A but the answer is C could someone explain it why, arent we suppose to use On instead of At in this case ?

答案是A
As后面为啥直接接名词呢？又不是as...as的形式。

下面详见Longman中对As，like的比较。
Grammar as, like, as if/though Use  as in comparisons in the expression  as ... as , with an adjective or adverb in between :  
Basketball is as popular as football here.
He can’t sing as well as his brother.
As is also used after  be the same (age/colour etc) :  
He is the same age as me.
?  Do not use  as on its own before a noun or pronoun in comparisons. Use  like :  
A movie is not like a book (NOT not as a book).
Like other people (NOT as other people), he values his privacy.
Use  as if/as though followed by a clause to compare a real situation to an imaginary situation :  
He talked to them as if they were children.
?   Some people use  like in this sort of comparison :  They act like they own the place.
However, some people think this is incorrect.
?  as if/as though cannot be followed directly by a noun :  
You treat them as if they were your parents (NOT as if your parents).




 

jessiecg

as+名词，表作为的意思
as+句子，表示动作的比较