Following are selected questions from internal control questionnaires about a company's customer order, credit, shipping, billing, and cash receipts functions. A yes response to any question would indicate a potential strength, and a no response a potential weakness of the system.

a. Are sales orders prepared for all approved customer orders?

b. Are copies of sales orders forwarded to the credit, shipping, and billing departments?

c. Is credit investigated before the customer is approved?

d. Are goods shipped only in accordance with approved sales orders?

e. Are shipping documents reviewed and compared with billings to assure that all shipped goods are billed?

f. Are all credit memos prenumbered, matched with approved sales orders and shipping documents, and checked for clerical accuracy?
g. Is the accounts receivable subsidiary ledger reconciled periodically with the general ledger?
h. Are mail receipts opened by personnel independent of shipping, billing, sales invoice processing, and recording?

Required: 

Assume that inquiries indicate the answer is yes to each question. For each question, draft a test you believe would provide persuasive evidence that controls are reliable.