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.
pledge noun [C]. âº a âserious or âformal âpromise, âespecially one to give âmoney or to be a âfriend, or something that you give as a âsign that you will âkeep a âpromise: [+ to infinitive] All the âcandidates have given/made pledges not to âraise âtaxes if they are âelected.