Dry mouth can be a result of nerve damage to the head and neck area from an injury or surgery. Dehydration . Conditions that lead to dehydration, such as fever, excessive sweating, vomiting, diarrhea, blood loss, and burns can cause dry mouth. Surgical removal of the salivary glands.
The Dewey decimal system is used in more than 200,000 libraries throughout the world and it has been translated into 35 languages. The Dewey decimal system, using numbers and letters, coordinates materials on the same subject and on related subjects to make items easier to find on the shelves..
A virtual library is  a digital space that keeps and organizes virtual books and their associated documents. It also can refer to a space where the books can be read. These spaces can include computers, mobile devices and the Internet. Some virtual libraries can be accessed for free, and others require subscriptions.