The definition of symbiosis has varied among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any type of persistent biological interaction (i.e. mutualistic, commensalistic, or parasitic).
The Golden Pledge, which is a System Plus Warranty with a 20 year leak guarantee, can pay for itself within the first ten years, sometimes many times over. The System Plus transforms the normal warranty by removing the small print.
From Wikipedia, the free encyclopedia. A Promise ring symbolizes a commitment to a promise and is given to a person as a token or reminder of his/her decision and may refer to: 1  Pre-engagement ring, a ring worn to signify a commitment to a monogamous relationship (a promise to commit to the relationship).