Introduction. Ocean trenches are natural tectonic plate boundaries between two crustal plates. When a continental plate converges with an oceanic plate a subduction zone forms. The heavier oceanic plate subducts beneath the lighter continental plate forming a trench.
Surgical-Medical Policy this patient has with Arkansas Blue Cross and Blue Shield provides coverage for dental. treatment only in case of accidental injury and accident-related damage to teeth, and then as a rule only to sound. natural teeth. A sound natural tooth is a tooth that is whole, free of decay, periodontal disease or other conditions, and is not in need of treatment for any reason other than accidental injury. DIAGNOSTIC X-RAYS AND THIS COMPLETED FORM ARE REQUIRED TO DETERMINE A. CONSIDERATION OF PAYMENT.
Audible Sound. Usually sound is used to mean sound which can be perceived by the human ear, i.e., sound refers to audible sound unless otherwise classified. A reasonably standard definition of audible sound is that it is a pressure wave with frequency between 20 Hz and 20,000 Hz and with an intensity above the standard threshold of hearing.