1.

- add 3:
  3

- add 4:
  4
 /
3

- add: 7
  7
 / \
3   4

- add: 0

    7
   / \
  3   4
 /
0

- add: 2

    7
   / \
  3   4
 / \
0   2

- add: 8

     8
   /   \
  3     7
 / \   /
0   2 4

- add 6:

     8
   /   \
  3     7
 / \   / \
0   2 4   6

2.

- first call gives us 8, then the resulting tree would be:

     7
   /   \
  3     6
 / \   /
0   2 4

- second call gives us 7, then the resulting tree would be:

     6
   /   \
  3     4
 / \ 
0   2

- third call givues us 6, then the resulting tree would be:

     4
   /   \
  3     2
 /   
0