jainaadeesh
i still couldnt understand both the questions...
why only "to attain" and "to enter" should be parallel and not "attaining" and "leaving"
"Attaining" and "leaving" can be appropriately used in a parallel structure.
1) Here is an example that uses a parallel structure:
"I graduated college early, attaining my goal and leaving before the job market crash."
The word "and" creates a parallel structure and requires that attaining and leaving be parallel.
2) This would not be parallel:
"I graduated college early, attaining my goal and to leave before the job market crash."
A participle and infinitive are not parallel.
3)This would be parallel but would have a different meaning:
"I graduated college early, to attain my goal and to leave before the job market crash."
Here, by using the infinitive, I give the impression that it was my strict intention to attain the goal and leave before the job market crash. Using participles suggests only the result of the prior action.
KW