What is a Promise Ring. A promise ring, sometimes known as a pre-engagement ring, is a simple piece of jewelry that is given as a symbol of a committed, monogamous relationship. In some cases, the promise ring symbolizes purity and a decision to remain celibate until marriage.
Noun. 1. external respiration-the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation. breathing, respiration, ventilation. artificial respiration-an emergency procedure whereby breathing is maintained artificially.
   Anaerobic respiration is the process by which non-oxygen dependent  organisms breath. It is mostly commonly used in the process of  fermentation.    Anaerobic respiration is respiration that uses electron acceptors  other than oxygen.Anaerobic respiration can be found in protozoans  and bacteria. Anaerobic respiration is a type of cellular respiration. It occurs  when oxygen is not available or is available in very low  quantities.It is also a respiration in the absence of oxygen.Oxygen is not used as the final electron acceptor.  Anaerobic respiration is the process by which non-oxygen dependent  organisms breath. It is mostly commonly used in the process of  fermentation.    Anaerobic respiration is respiration that uses electron acceptors  other than oxygen.