Question 1 : Yes, the statement is justified.
A square has 4 equal sides and it has 2 pairs of parallel sides, just like a rhombus. However, a rhombus need not be a square. The internal angle of both a square and a rhombus is the same,360°,but, a square's sides are all of angle 90°,unlike a rhombus where 2 sides are the same,but another 2 sides are different.Which means that not all the sides are of the same angle.
Question 2 : D
Both a square and a parallelogram have 4 sides, which make them an quadrilaterals.
Both a square and a parallelogram have opposite sides that are parallel. The top and bottom side,and as well as the left and right side of both a square and parallelogram are parallel.
A trapezoid only has one pair of parallel lines because the other two lines are not parallel. Thus it only has 1 pair.
Question 4 :
I do not agree with this statement.Not all parallelograms are squares as all the angles of a square are 90° but not all sides of the parallelograms are 90°.