Write down all the subsets of the following set: $\emptyset $

Write the following interval in set-builder form: $(-3, 0)$

Make correct statements by filling in the symbols $\subset$ or $\not\subset$ in the blank spaces:
$\{a, b, c\} \dots \{b, c, d\}$

Given the sets $A = \{1, 3, 5\}$,$B = \{2, 4, 6\}$,and $C = \{0, 2, 4, 6, 8\}$,which of the following sets can be considered as a universal set for all three sets $A$,$B$,and $C$?

List all the elements of the following set:
$F = \{ x : x \text{ is a consonant in the English alphabet which precedes } k \}$

The number of elements in the set $\{ (a, b) : 2a^2 + 3b^2 = 35, a, b \in Z \} $,where $Z$ is the set of all integers,is