Indirect ways of assessing past temperatures, using so-called temperature proxies, take measurements of responses to past temperature change that are preserved in natural archives such as ice, rocks and fossils.
Wikipedia has an article on: Reorder tone. Wikipedia. fast busy signal â(plural fast busy signals) (telephony) An audible signal on a voice phone line that sounds more frequently than a standard busy singal, indicating that no transmission path to the called phone number is available.
Definition of signal for Students. 1  1 : a sign, event, or word that serves to start some action â¦ the manager gave the signal for the curtain to go down, and the audience â¦ cheered. 2  2 : a sound, a movement of part of the body, or an object that gives warning or a command The police officer made a signal with his hand. a traffic signal.