In 3-5 complete sentences, explain how Islam expanded across Asia, Africa, and Europe.

First, Arab traders came from Asia into North Africa. They moved across the Sahara into West Africa. Later on, other merchant traders came by boat to the east coast. Islam spread as ivory, salt, slaves, gold, and many other items were traded and sold.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.