It might either be diaphragm or a coil.
not sure but hope it helps.
The answer to the blank space in the given question is (C) conductors.
Conductors are<em> objects that can be used to make electrical current or heat flow from the source to a target object.</em> Some objects are better conductors than others due to its materials. For example, objects made from metals are always better conductors than objects made from wood or glass.
An online travel agency such as Travelocity is an example of a intermediary.
It is to avoid plagiarizing someone else's work
Explanation:
the answer in the image above
