her is this from google
"A system of temporary reference points established in the field allows users to move freely within the study area without losing the geo-referencing. It allows the user to perform the mapping of trees, deadwood, transects, repeated measurements and data verification."
Hey there!
Oligarchy is rule by the rich, usually aristocrats. They indeed did not get their money in an honest way. In most oligarchies, they made laws that benefitted themselves, like unfair tax and odd charges. A common outcome of this type of government is making the rich richer and the poor poorer.
Hope this helps!
The cretaceous-tertiary mass extinction was apparently caused by a meteorite that struck Yucatan Peninsule in Mexico
