2. For every action there is an equal and opposite reaction.
"action...reaction" means that forces always occur in pairs. Single, isolated forces never happen. The two forces involved are called the "action force" and the "reaction force.
Either force in an interaction can be the "action" force or the "reaction" force.
People associate "action" and "reaction" with "first an action, then a reaction" - as in, first Suzie smacks Johnnie (action) then Johnny says "Mommy! Suzie hit me!" (reaction). That is NOT what is going on here! The action and reaction forces exist at the same time.

3. For every action there is an equal and opposite reaction.
equal" means two things:
Both forces are exactly the same size. They are equal in magnitude.
Both forces exist at exactly the same time. They both start at exactly the same instant, and they both stop at exactly the same instant. They are equal in time.

4. For every action there is an equal and opposite reaction.
opposite" means that the two forces always act in opposite directions - exactly 180o apart.

5. A pushes/pulls B.
B pushes/pulls A.
One of these forces is called the action force, and the other one is called the reaction force - it doesn't matter which is which. For example, if:
You push book. (Action force)
then Newton's Third Law says that:
Book pushes you. (Reaction force)

6. True or False
If “you push a book” is considered the action force, the reaction force is “book pushes you”

7. A soft ball player catches a ball
A soft ball player catches a ball. If the action force is the force the ball exerts against her glove, what is the reaction force in this interaction?
The force the glove exerts on the ball
The weight of the ball
Friction force of the ground on her shoes
The force the player’s hand exerts on the glove
The force the Earth exerts on the glove.

8. A softball player hit the ball with a bat
A softball player hit the ball with a bat. If the action force is the force exerted by the bat on the ball, what is the reaction force in this interaction?
The force that the ball exerts on the bat.
The force of the players hand on the bat.
Air resistance force on the ball
The weight of the ball
None of the above.

9. As a rock falls toward the Earth, suppose that the action force is the pull of the Earth on the rock. What is the reaction force?
The pull of the rock on the Earth
Air resistance acting on the rock.
Gravity
There is no reaction in this case.
The acceleration of the rock.