My question is about this sentence:
1) correct: "The beauty of the desert lies not in its lushness, but in its isolation."
2) wrong: "The beauty of the desert lies not in its lushness, but its isolation."
Is sentence #2 wrong? Why? I know the standard answer about parallelism of correlative conjunctions — but what about sentences like the one below, in which gapping allows for certain omissions. Can gapping legitimate the omission of the preposition in #2.
3) "Fred tries to treat his parents well, and they, him." (From this link about gapping: http://dickhudson.com/wp-content/uploads/2013/07/gapping.pdf.)