Make correct statements by filling in the symbols $\subset$ or $\not\subset$ in the blank spaces:
${ x:x \text{ is an equilateral triangle in a plane} } \dots { x:x \text{ is a triangle in the same plane} }$

Assume that $P(A) = P(B)$. Show that $A = B$.

Which of the following is a set? Justify your answer.
$A$ team of eleven best cricket batsmen of the world.

In a city,no two persons have an identical set of teeth,and there is no person without a tooth. Also,no person has more than $32$ teeth. If we disregard the shape and size of the teeth and consider only the presence or absence of a tooth at each of the $32$ positions,then the maximum population of the city is:

Which of the following is a set? Justify your answer.
The collection of all even integers.

List all the subsets of the set $\{-1, 0, 1\}$.