Which statement is true? A. All parallelograms are rectangles.
B. All parallelograms are quadrilaterals.
C. All quadrilaterals are parallelograms.
D. All rectangles are squares.

A parallelograms are rectangles

B.All parallelograms are quadrilaterals.

Step-by-step explanation:

A. Not all parallelograms are rectangles but all rectangles are parallelograms

C. Not all quadrilaterals are parallograms, for example the trapizoid isnt a parallogram but it is a rectangle

D. Not all rectangles are squares because they don't all have 4 equal side lengths. But all squares are rectangles

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.