When Xiao Li was decorating the house, he went to a brand store and bought a wooden floor. Through the following two experiments, the boss took his own membrane brand wooden floor and someone else's G

(1) When comparing the density of two brands of wood flooring, it is necessary to control the volume of the two kinds of wood flooring to be equal, that is, the length, width and thickness of the two kinds of wood flooring are equal;

(2) In the experiment of comparing the surface hardness and wear resistance of wood floors, it is necessary to ensure the pressure of sand bricks on the floor when the same rectangular sand brick rubs back and forth on two wood floors respectively; The number or length of rubbing of sand bricks on the floor; Location and contact area of sand brick and floor.

So the answer is:

(1) thickness

(2) the pressure of sand brick on the floor; The number or length of rubbing of sand bricks on the floor; Location and contact area of sand brick and floor.