Answer:
Law of Effect.
Explanation:
Edward L. Thorndike (1874-1949) was an American psychologist and researcher, and one of the pioneers of behavioral psychology. Thorndike's experiments with cats led him to discover a psychological pattern he called the Law of Effect. According to this law, if faced with similar or recurring situations, we tend to repeat the behaviors that resulted in satisfying or positive consequences, while we don't tend to repeat the behaviors that resulted in unpleasant or negative consequences. One application of this principle was a learning method based on rewards and punishments called operant conditioning, developed by another well-known American psychologist and author, B. F. Skinner, in the early 20th century.
As of 2009, Sunni Muslims constituted 87–90% of the world's Muslim population-
the Shia believe that leader is called an imam and this "caliph/imam" should be a direct descendant of Mohammed-
and I have no clue on the last one
A clinical trail
Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. These studies also may show which medical approaches work best for certain illnesses or groups of people. - Definition by <span>https://www.nhlbi.nih.gov/studies/clinicaltrials</span>
It divides the world into hemispheres.
