List all the elements of the following sers :

$E = \{ x:x$ is a month of a year not having $ 31 $ days ${\rm{ }}\} $

Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:

$ 8\, .......\, A $

Examine whether the following statements are true or false :

$\{ a,b\}  \not\subset \{ b,c,a\} $

Make correct statements by filling in the symbols $\subset$ or $ \not\subset $ in the blank spaces:

$\{ x:x$ is an even natural mumber $\}  \ldots \{ x:x$ is an integer $\} $

Examine whether the following statements are true or false :

$\{ a,e\}  \subset \{ x:x$ is a vowelin the English alphabet $\} $

Make correct statements by filling in the symbols $\subset$ or $ \not\subset $ in the blank spaces:

$\{ x:x$ is an equilateral triangle in a plane $\}  \ldots \{ x:x$ is a triangle in the same plane $\} $