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Electric bell is placed under a bell jar where the air is vacuumed through a hose. Sound becomes less and less audible. Bell jar experiment to prove sound requires a medium to travel.
Facts vs Myths
KYC or know your customer with business verifying the identity of its client's concept at the partners-to-be through a magnifying glass of business identification and safety.
Confirmed typically means that something has been verified, approved, or validated to be true, accurate, or definite, text concept stamp

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