Binary Search Trees - General Questions

Which self-balancing tree is used by many standard libraries' ordered maps?

Deleting a node with two children from a BST replaces it with its:

The keys 60, 75, 45, 15, 25, 50, 20 are inserted in this order into an empty binary search tree. What is its postorder traversal?

The keys 75, 70, 15, 20, 40, 45, 30 are inserted in this order into an empty binary search tree. What is the height of the tree (number of levels)?

The keys 30, 20, 75, 25, 40, 35, 80 are inserted in this order into an empty binary search tree. What is its preorder traversal?