（複選）Please successively insert the data pairs containing the following keys into an empty height-based min leftist tree: 10, 20, 30, 40, 50, 60, 70, 5, 4, 15, 16. After each insertion, the tree should still be a min leftist tree. Which of the following descriptions are correct for the resultant tree?

Note: In a tree, each step from top to bottom is called the level of a tree. The level count starts with 1 and increments by 1 at each level or step.