Essential Part 2
Hurricane is a violent storm accompanied by strong winds. It cannot exist without winds.
An autograph refers to the signature of famous personalities. It cannot exist without a signature.
A faculty is a group of teachers, and it cannot exist without teachers. Faculty may teach in a school, use textbooks, or attend meetings, but these are not essential parts.
When an object starts vibrating it causes motion; it cannot be still when it vibrates.
A glacier is a huge mass of ice which is made up of snow. It cannot exist without ice.
Essential Part 1
Essential Part 3
Essential Part 4