1-1The inorder traversal sequence of an AVL tree must be in sorted (non-decreasing) order.TAVL 树的中序遍历序列必须是有序（非递减）顺序1-3An AVL tree with the balance factors of all the non-leaf nodes being 0 must be a p

1-2Let S be the set of activities in Activity Selection Problem. Then there must be some maximum-size subset of mutually compatible activities of S that includes the earliest finish activity a mT1-3令S