5.tower of hanoi problem can be solved efficiently using recursion t/f

6.where as lists,stacks and queuees have a linear structure, binary trees have a ___ structure

9.at most,how many neighbors will a node in a binary tree have?

at most, how many children will a nod in a binary tree have?

10.the node at the top of a binary tree has a special name called?

11.in a binary tree, all nodes to the left of the currect node are (latger or smaller)than the current code.