Believed to originate from a small area on their foreheads, elephants emit low-frequency sounds that may be used as a secret language to communicate with other members of the herd.
(A) Believed to originate from a small area on their foreheads, elephants emit low-frequency sounds that may be used
(B) Elephants emit low-frequency sounds that are believed to originate from a small area on their foreheads, and they may use this
(C) Elephants emit low-frequency sounds, believed to originate from a small area on their foreheads, that they may use
(D) Originating, it is believed, from a small area on their foreheads; elephants emit low-frequency sounds they may use
(E) Originating, it is believed, from a small area on their foreheads, low-frequency sounds are emitted by elephants that may be used
https://www.nytimes.com/1986/02/11/science/secret-language-found-in-elephants.htmlELEPHANTS emit low-frequency vocal sounds, inaudible to man, that may be used as a ''secret'' language to communicate with other members of a herd over both long and short distances, researchers at Cornell University have discovered.
The sounds, believed to originate from a fluttering spot on the giant animals' foreheads, are at frequencies in the range of 14 to 24 hertz, below the threshold of human hearing.