The root directory, or root folder, is the top-level directory of a file system.
Bluetooth is the most reasonable answer
The answer is 1, the 3rd circle
Answer:
The phenomenon of total internal reflection of light is used in many optical instruments like telescopes, microscopes, binoculars, spectroscopes, periscopes etc. The brilliance of a diamond is due to total internal reflection. Optical fibre works on the principle of total internal reflection.
Explanation:
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