template ____ doublyLinkedList::isEmptyList() const{   
  return (first == nullptr);}
Consider the accompanying statements. The operation returns true if the list is empty; otherwise, it returns false. The missing code is ____.

With a(n) _________________________ topology, a transmission moves from node to node around a circle in a clockwise direction.

Fill in the blank(s) with the appropriate word(s).

Which of the following statements accurately describe National Security Letters ("NSLs")?

A. They may only be issued by officials in CIA headquarters. B. They may not contain nondisclosure provisions prohibiting the recipient from disclosing the contents of the letter. C. They may only request information pertaining to a foreign power or the agent of a foreign power. D. They do not require prior judicial authorization.