Answer:
Step-by-step explanation:
The explanation involves another Newton's law: his second law of motion says force is a product of mass and acceleration.
When a small object is dropped on Earth, gravity pulls the object down towards Earth. The same mutually attractive gravity force also pulls Earth towards the object. But as mass of Earth is much larger than that of the small object, the acceleration of Earth and hence its movement toward the object will be much smaller as to be not noticeable.