(Select all that apply.) (a) The person exerts a normal force down and to the right on the lawnmower. Which of the forces listed makes a Newton's 3rd Law pair with this force? (select all that apply) downward normal force on the ground by the lawnmower upward normal force on the lawnmower by the ground upward gravitational force on the Earth by the lawnmower normal force on the person by the lawnmower upward and to the left X