<p>"A healthy economy can be measured not only by the growth of business but also by the psychological effect on people."</p>
<p>In this sentence, can I omit the latter "by" to form the parallelism?</p>
<p>There are two sentences:
1."Overall, the positive of team-sports participation far outweigh the negatives."
2."Overall, the positive of participating in team-sports far outweigh the negatives."</p>
<p>Why does the book say the former one is incorrect? It regard "team-sports participation" in the former one as a mouthful. If so, the "participating in team-sports" can also be redundant. Puzzled.</p>
<p>"Early American factories did not so much replace household manufacturing but complement it."</p>
<p>I think the sentence is OK. Is it necessary to change "but" into "as"?</p>
<p>hi chenwei:</p>
<p>in the very first sentence, the two "by"s can't be omitted (on the SAT) because they're what makes the parallelism. without those repeated prepositions, there's nothing parallel in the sentence.</p>
<p>in the pair of sentences about team sports, the problem is that the SAT doesn't like to see nouns modified with other nouns. "team sports participation" uses the noun phrase "team sports" to modify the noun "participation." in the second sentence, this problem is solved by changing "team sports" to the indirect object of the verb "participating."
(note that, for some reason, the SAT still thinks it's okay to modify the noun "sports" with the noun "team"--yet another example of internal inconsistencies in the SAT's prescribed grammar. don't worry, though, as the questions are constructed so that this will never be a problem from a test-taking perspective.)</p>
<p>for the last sentence, "as" is better than "but." search the forums for a thread on coordinating conjunctions, which had a list of similar constructions that would be good to know.</p>