Which kind of variable can be initialized only once?

Which of the following is not a red-black tree property?

a. the root is black b. all leaves are black c. consecutive red nodes are disallowed d. every path from a node to an external node must contain the same number of black nodes e. all of the above are red-black tree properties

Clicking either the Date & Time button or the ____ button opens the Header & Footer dialog box.

A. Slide Date B. Slide Time C. Slide Number D. Slide Title