Revise the subsequent sentences for brevity and professionalism. Explain the changes you made to the sentences and rationale for making the change.
1. In the event there is an emergency we will contact your emergency contact listed.
2. He stopped going to class on account of the fact that it was essential for him to get a new car because his car broke down.
3. In respect of what you said, I do agree that the new healthcare law is not going to be effectual due to the number of people without money it is affecting.
4. In the company that I work for there are wide-open opportunity for professional development and it is a company that enjoys an enviable record for constancy in the dynamic atmosphere of healthcare.