The organisms in the Cretaceous period and Permian Period are now extinct.
The emergence and demise of specific living forms are represented by time periods on the geologic time scale that span hundreds of millions of years. A mass extinction is a period of geologic time when a large number of plant and animal species go extinct, sometimes within a few thousand to a few million years.
Life has recovered after each of the five significant mass extinctions that have taken place during the past 500 million years. Because it led to the extinction of the dinosaurs, the mass extinction at the end of the Cretaceous Period is the most well-known. However, the Permian Period's end saw the most extreme one in terms of the number of species destroyed.
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Answer: Positive
Explanation:
Positive reinforcement is defined as process in which something is given or praising the person in form of reward when he/she performs any desired act .It helps in promoting and performing such acts more in future by the person through reinforcement stimulus.
According to the question, as Leah has completed her reading task as well as assignments, she is rewarding herself with movie treat so that she can promote her on-time reading function more in future.Thus, it is positive reinforcement example.
The two types of drama the Greeks preformed at religious festivals was comedies and tragedies.
