One reason trade from the area around ghana and mali may have been favored is that

With any turning vehicle, the rear wheels follow a shorter path than the front wheels. the longer the vehicle is, the greater the difference will be. truck drivers initially swing out before making a turn. what isn't shown in this illustration is as car straightens out, the front wheels must travel a greater distance and the tail end drags on the shortest path.

B.  earth orbits at a slower rate than the rate at which the moon orbits earth.

Each eukaryotic cell has a plasma membrane, cytoplasm, a nucleus, ribosomes, mitochondria, peroxisomes, and in some, vacuoles; however, there are some striking differences between animal and plant cells.