Answer:
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B. Switch</h2>
Explanation:
<u>A device designed to open or close a circuit under controlled conditions is called a switch. The terms “open” and “closed” refer to switches as well as entire circuits. An open switch is one without continuity: current cannot flow through it.</u>
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Answer:

Explanation:
Bulk modulus is defined as the relative change in the volume of a body produced by a unit of compressive acting uniformly over its surface:

Hence the density of the seawater at a depth of 680atm is calculated as:-

The answer would be B. :)
True, I'm not the best when it comes to science, but I'm pretty sure it's this