Fill in the blanks to make each of the following a true statement :

$A \cup A^{\prime}=\ldots$

Let $U=\{1,2,3,4,5,6,7,8,9,10\}$ and $A=\{1,3,5,7,9\} .$ Find $A^{\prime}$

If $U=\{a, b, c, d, e, f, g, h\},$ find the complements of the following sets:

$C=\{a, c, e, g\}$

If $U =\{1,2,3,4,5,6,7,8,9\}, A =\{2,4,6,8\}$ and $B =\{2,3,5,7\} .$ Verify that

$(A \cap B)^{\prime}=A^{\prime} \cup B^{\prime}$

Let $U = \{ 1,\,2,\,3,\,4,\,5,\,6,\,7,\,8,\,9,\,10\} $, $A = \{ 1,\,2,\,5\} ,\,B = \{ 6,\,7\} $, then $A \cap B'$ is