premise: the radioactive isotope content of a rock means the amount of elemental isotopes of the parent isotopes sent2: radiometric dating is used to identify / determine the absolute age of the rock sent3: the absolute age of a rock is the amount of time passed since a rock was formed sent4: radiometric dating is a kind of method to determine the absolute age of the rock sent5: calculating the age of rocks requires investigating the original amount of the elemental isotopes of the parent isotopes.
hypothesis: timber companies can manage the number of trees in a forest by planting trees to replace what they cut down