What audit procedures can auditors run during audit engagements to obtain audit evidence? Which audit assertion(s) does each audit procedure helps to test? Make sure to explain each audit procedure and give examples if necessary. Explain what types of audit opinions auditors can issue and what are the possible reasons for issuing these opinions? Furthermore, discuss the circumstances that require auditors to modify the standard report but not the audit opinion. Discuss how important is the risk assessment stage in audit engagements? Explain what audit procedures auditor perform in this stage and how the results of these procedures would affect the other stage of the audit