The answer is Seismoscope
Many things including protests
The correct answer in the missing blank is known as "separation".
The six degrees of separation is known as a theory in social networking wherein it states that a person can be connected anyone in the world, no matter how far, through a process of acquaintances, which possesses not more than five mediums.
A plebiscite is like an vote
Definition - A vote by people of an entire country or an district to decide the issues
