Usage of "Begin" on GMAT

[pawanugt]

Dear Stacey / Ron

Request you to kindly help me with the usage of Begin.

1. The discussion must begin with a new idea.

2. The discussion must begin by identifying the problem.

3. The discussion must begin on the right note.

Please explain the difference in the above mentioned usages.

Regards
Pawan

[tim]

well, the difference is that you're discussing three completely different things! if you're asking which prepositions you can use, there are appropriate ways to use each of the prepositions you've listed..