Edit the following sentences for tone. Remove negativity to achieve a more professional tone.

1. I cannot speak at graduation this year because I have something more important scheduled.
2. You better get that proposal in by the end of the day.
3. I will not be sending your company the rest of the order until you pay your account in full.
4. I'm not sure what you are doing with that proposal, but it needs to be revised immediately.
5. Because you did not give us a copy of the receipt, you will not be getting a refund.