Santa Monica College Auditing And Financial Statements Discussion

please answer to the questions related to the auditing. I’m gonna attach my professor slides . one small paragraph is enough.

1) What must external auditors do to use the work of internal auditors in the audit of an entity’s financial statements?

2)What must external auditors do to use the work of audit specialists in the audit of an entity’s financial statements?

3)What benefits are obtained by having an engagement letter?

4)What sources of information can auditors use in connection with deciding whether to accept a new client?

5)What is the difference between vouching and tracing? Provide an example of each.