Which sentence uses commas or semicolons correctly? the keys to happiness are living; loving and laughing. the keys to happiness are living, loving, and laughing. the keys to happiness are living, loving and laughing. the keys to happiness are living; loving; and laughing.

  this riddles' answer is library.

  the "leaves" are a reference to the books' pages that the library contains; the branches are a network of libraries that connect multiple libraries' collections, resources, and items in a system of a common database, integrating them; the branches' organization are a useful management tool for coordinating the multiple collections many libraries have.