If you test more than one variable in an experiment at a time than you wouldn't know what variable caused the change in the end.
Answer: was to increase the population of wolves
Explanation: The reasoning behind introducing these gray wolves (Canis Lupus) to the Greater Yellowstone Ecosystem was to increase the population of wolves there since they were once scattered because of people killing these animals off with the assumption that they were predators and were viewed as dangerous animals.
The ECT treatment includes electric stimulus used to produce a generalized seizure. Professionals using electroconvulsive shock therapy (ECT) for patients suffering from severe depression have shown that the memory processes of consolidation may take years to return.