The degree sequence of a simple graph is the sequence of the degrees of the nodes in the graph in decreasing order. Which of the following sequences can not be the degree sequence of any graph?
$${\rm I}.$$$$\,\,\,\,\,7,6,5,4,4,3,2,1$$
$${\rm I}{\rm I}.$$$$\,\,\,\,\,6,6,6,6,3,3,2,2$$
$${\rm I}{\rm I}{\rm I}.$$$$\,\,\,\,\,7,6,6,4,4,3,2,2$$
$${\rm I}V.$$$$\,\,\,\,\,8,7,7,6,4,2,1,1$$

A binary tree with $$n>1$$ nodes has $${n_1}$$, $${n_2}$$ and $${n_3}$$ nodes of degree one, two and three respectively. The degree of a node is defined as the number of its neighbours.

Starting with the above tree, while there remains a node $$v$$ of degree two in the tree, add an edge between the two neighbours of $$v$$ and then remove $$v$$ from the tree. How many edges will remain at the end of the process?

A binary tree with $$n>1$$ nodes has $${n_1}$$, $${n_2}$$ and $${n_3}$$ nodes of degree one, two and three respectively. The degree of a node is defined as the number of its neighbours.

$${n_3}$$ can be expressed as:

$$G$$ is a graph on $$n$$ vertices and $$2n-2$$ edges. The edges of $$G$$ can be partitioned into two edge-disjoint spanning trees. Which of the following in NOT true for $$G$$?