Question

No system is completely closed off from its surroundings, but some systems are almost completely closed.

Which represents a system that is almost completely closed?

A.
a metal file cabinet

B.
a glass bottle

C.
an insulated thermos

D.
a small island

Answer 1

A closed system is a system in which nothing can get in or out.
With that in mind, A metal file cabinet can easily get items in and out from cracks/seams.
A glass bottle (Assuming it does not have a lid) can easily have items seep through the neck.
A small island is completely open to everything.
So, that leaves us with C. An insulated thermos.
An insulated thermos is almost completely closed off to everything. It is an almost completely closed system.
C is your answer.