[讨论]OG11th-97

      97. The stars, some of them at tremendous in motion just as the planets are, yet being so far away from Earth that their apparent positions in the sky do not change enough for their movement observed during a single human lifetime.

(A)         The stars, some of them at tremendous speeds, are in motion just as the planets are, yet being

(B)         Like the planets, the stars are in motion, some of them at tremendous speeds, but they are

(C)         Although like the planets the stars are in motion, some of them at tremendous speeds, yet

(D)        As the planets, the stars are in motion, some of them at tremendous speeds, but they are

(E)         The stars are in motion like the planets, some of which at tremendous speeds are in motion but

选B？用like表达比较的意思？

agree

some of them at tremendous speed

在句子中起什么作用?

Can anybody tell why does not  choose D

AS如果在这里作为介词表示举例而不是比较

同问D为什么不行呢？

as并不一定表示举例阿。这里的as应该表示“像、如同”的意思。“像行星一样，恒星是运动着的...，但是...”这样解释对不对呢？如果对的话，为什么一定要用like？

多谢解答~

as后面必须加句子：表示像。。。。

like后面加名词：表示像。。。。

所以D as+名词是错误的

因为as+名词，不表示像。。。。。而表示“作为。。。。。”

有关as 和like的用法，OG11 在SC题目前面的指导中描述的比较清楚

as/like
As can be a preposition meaning "in the capacity of", but more often is a conjunction of manner and is followed by a verb
Like is generally used as a preposition, and therefore is followed by a noun, an object pronoun, or a verb ending in "ing"

也就是说， as在GMAT中的绝大多数情况下一定是要连接clause的，要有完整的subject和verb；而like一定是要连接phrase来表示比较关系的，类似的还有unlike；

关于as的解释 有一点我跟gonghao同学有不同的看法 就是GMAC虽然偏向as后面加句子 但是不是绝对的 不是必须要加句子 有一道题就是

OG-Purple-SC-87

The diet of the ordinary Greek in classical times was largely vegetarian-vegetables, fresh cheese, oatmeal, and meal cakes, and meat rarely.

(A) and meat rarely

(B) and meat was rare

(C) with meat as rare

(D) meat a rarity

(E) with meat as a raity

这个取决与as的功能 还有表示的意思 as可以作为介词 也可以为连词 介词后面当然接名词 意思是"当作" 或者表明身份职业 跟like表达的东西不一样 A as adj./adv. as B 这种情况可以表比较 单独as不能表比较 原句有comparision的意味 所以不能用as