Homologous structures are </span><span>similar structures shared by different species. For example, the anatomy of joints in bones of birds and dinosaurs, support the idea that these two groups have a common ancestor. But since these two groups are different enough to be separated into different classes, it can be concluded that they evolved from the common ancestor.</span>
The correct formula for population growth is the individuals added to the population via birth or immigration, minus the individuals removed from the population via death or emmigration. Therefore the answer is (B+I)-(D+E), or B+I-D-E
Air mass motion is usually from the air flow in the upper atmosphere. As a stream changes intensity, and position, it affects motion, and strength of air masses.
