<span>This variation be justified by:
</span>Migration to an environment different from their birthplace, and adaptation to the available food, ultimately leading to speciation. because <span>birds use their beaks to eat.</span>.
Answer:
because they have thicker walls
Explanation:
blood is punped our of the heart very fast which means it would need a blood vessel witch thick walls to withstand the pressure. thin walls would cause the blood vessle damage and may evwn break as it wouldn't be able to withstans the pressure.
They engulf using their pseudopodia
Answer:
stomach acid< urine< blood
hope this answer help.
Iris is the muscle that regulates the amount of light entering the eye