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.
In about 10% of normal newborn babies, the tear duct that drains the tears from the eye to the back of the nose is blocked. It causes the eye to be watery and prone to infections and discharge. Most blocked tear ducts will open up on their own by 6-12 months of age.