OFFICIAL EXPLANATIONProject SC Butler: Sentence Correction (SC1)
THE PROMPTQuote:
Like many ectotherms, a term formerly used to describe cold-blooded animals, some frog species lay their eggs in sunlit ponds or puddles, and they expressly rely on the sun’s energy for speeding up egg hatching, for larval development, and metamorphosis before the pond dries up
THE OPTIONSThe use of relying is a logical way to convey the result of frogs laying their eggs in sunlit ponds or puddles.
Quote:
A) some frog species lay their eggs in sunlit ponds or puddles, and they expressly rely on the sun’s energy for speeding up egg hatching, for larval development, and metamorphosis
• idiom
→
for speeding up is not idiomatic;
to speed up is idiomatic
We rely on something
to do something and not
for doing something.
• EDIT: the list is not parallel
→ The three items in the list—
for speeding up egg hatching, for larval development, and
metamorphosis—are not parallel.
Use the preposition for before only the first list item (preferred) or before all three items, but not before only two of three.
Original takers, your list was parallel. I was reading the OE for this question and it mentioned what you now see in this answer analysis. I edited the question.
• construction
→
and they expressly rely is not exactly wrong, but the phrasing is not as effective as that in option B: [comma + relying].
The use of
relying is a logical way to convey the result of frogs laying their eggs in sunlit ponds or puddles.
The use of comma + ___ING word is a signal in English that the verbING word may well present the result of the previous clause.
Quote:
B) some frog species lay their eggs in sunlit ponds or puddles, expressly relying on the sun’s energy to speed up egg hatching, larval development, and metamorphosis
• I do not see any errors
→
Quote:
C) some frog species laying their eggs in sunlit ponds or puddles, and expressly relying on the sun’s energy to speed up egg hatching, larval development, and metamorphosis
• Fragment - the main clause is missing a verb.
→
laying should be
lay→
relying should be
relyELIMINATE C
Quote:
D) some frog species’ eggs are laid in sunlit ponds or puddles, and they expressly rely on the sun’s energy to speed up egg hatching, larval development, and metamorphosis
• Bad comparison
→ The sentence begins with "Like many ectotherms."
Ectotherms are cold-blooded animals.
Ectotherms cannot be logically compared with frog species’
eggs.
• voice shift
→ on the GMAT, do not shift in mid-sentence from active to passive voice or from passive to active voice.
The sentence begins in passive voice (
eggs are laid), shifts gears, and ends in active voice (
they rely)
This issue is one of construction and style. Keep the voice consistent: all passive or all active.
• pronoun issue
→ does
they refer to
eggs (probably) or
ectotherms (more logical)?
I would not eliminate this option based only on this issue. True pronoun ambiguity is fairly rare on the GMAT.
But the lack of clarity could be a tie-breaker, if option D were a contender for "last two options standing."
ELIMINATE D
Quote:
E) some frog species that lay their eggs in sunlit ponds or puddles expressly rely on its energy for speeding up egg hatching, larval development, and metamorphosis
• missing antecedent
→ the pronoun
its has no antecedent. No sun is mentioned.
• idiom
→
for speeding up is not idiomatic;
to speed up is idiomatic
We rely on something
to do something and not
for doing something.
The answer is B. COMMENTSMost of these explanations include some very astute and subtle analysis.
Good looking out!
Stay safe, everyone.