The more commonly used light-year is also presently defined to be equal to precisely 7007315576000000000â 31557600 light-seconds, since the definition of a year is based on a Julian year (not Gregorian year) of exactly 365.25 days, each of exactly 7004864000000000000â 86400 SI seconds.
Keystone resource a component of the environment utilized by individuals in the ecological community without which the individuals would not thrive or without which the ecological community structure would be negatively effected. Kin selection
The Keystone Pipeline System is an oil pipeline system in Canada and the United States, commissioned since 2010.It runs from the Western Canadian Sedimentary Basin in Alberta to refineries in Illinois and Texas, and also to oil tank farms and oil pipeline distribution center in Cushing, Oklahoma.he Keystone Pipeline System is an oil pipeline system in Canada and the United States, commissioned since 2010.