List all the elements of the following sers :

$A = \{ x:x$ is an odd natural number $\} $

Which set is the subset of all given sets

Write the following intervals in set-builder form :

$\left( { - 3,0} \right)$

Write the set $\{ x:x$ is a positive integer and ${x^2} < 40\} $ in the roster form.

In each of the following, determine whether the statement is true or false. If it is true, prove it. If it is false, give an example.

If $x \in A$ and $A \in B,$ then $x \in B$