More than 30 years ago Dr. Barbara McClintock, the Nobel Prize winner, reported that genes can "jump," as pearls moving mysteriously from one necklace to another.
as pearls moving mysteriously from one
necklace to another
like pearls moving mysteriously from one
necklace to another
as pearls do that move mysteriously from one
necklace to others
like pearls do that move mysteriously from
one necklace to others
as do pearls that move mysteriously from one
necklace to some other one
Clauses have subjects and verbs and are introduced by conjunctions or relative pronouns; phrases do not have subjects and verbs and are frequently introduced by prepositions. The preposition like, not the conjunction as, should introduce the underlined phrase.
A As incorrectly introduces a phrase when like is required
B Correct. In this sentence, the preposition like properly introduces the phrase.
C McClintock's simile creates an image that is not real; the use of the verb do indicates the pearls' movement as a reality
D Like incorrectly introduces a clause; the verb do indicates a reality instead of an image that is only imagined
E Pearls do not actually move; McClintock is suggesting an image only. Some other one is a wordy replacement for another
答案是B , 但是我不太明白ETS的解释,为什么不能用AS , 是说 这只是个比喻而不是真的,所以只能用like , 不能用as 嘛? 如果这样用as 可以嘛? as pealrs move mysteriously from one necklace to another | 
