Every node (except of the last node) in a singly linked list contains

When is an original work considered public domain? a. when posted via social media b. when it is posted on the internet c. when a copyright symbol is not included with the piece of work d. when explicit permission is given by the author / owner

Which of the following is not an enhancement to the standard wiki to make it more attractive for corporations? encryptionwork spacespermission toolspredictive text

Does anybody know how to hack into a google account? i had important information on it and it is gone now and i need getting it back.