How should I record my business transactions? Purchases, sales, payroll, and other transactions you have in your business generate supporting documents. These documents contain information you need to record in your books. What is the burden of proof? The responsibility to substantiate entries, deductions, and statements made on your tax returns is known as the burden of proof.
Mice will probably open their eyes when they're about 10-14 days  old. About the time the hair is fully covering them they open their  eyes.
Chihuahua puppies first open their eyes 10 to 16 days after they are born. Their eyes are sealed from the time they are born until this happens.