Answer:
the pain he feels when he is hungry
Explanation:
Black Boy is a memoir that was written by the author Richard Wright in which he describes in detail what it was like for him growing up in the South as well as moving to Chicago in order to start his career. In this memoir he associates the bitterness and pain he feels over being abandoned by his father with the pain he feels when he is hungry
The four important characteristics of respiratory surface are:
1. Thin walls
2. Moisture
3. Large surface area
4. Blood supply
Respiratory system or respiratory tract is divided into upper and lower tract. Upper respiratory tract includes nose and its cavities, sinuses, pharynx and the part of the larynx. Lower respiratory tract consists of the trachea, bronchi, bronchioles and the alveoli.
Alveoli are the ends of the respiratory tract the smallest units in it. Alveoli are small folded air sacs that are branching off from alveolar ducts and providing an extremely large surface area for the gas exchange. Gas exchange occurs thanks to small blood vessels – capillaries that surround alveoli and it occurs via the process of diffusion.
So, respiratory surface is thin membrane also known as the blood–air barrier that consists of the alveolar epithelial cells, their basement membranes and the endothelial cells of the alveolar capillaries.
Answer: no body cavity—acoelomates; body cavity not completely lined with mesoderm—pseudocoelomates; body cavity completely lined with mesoderm—coelomates
Homeostasis is the property of living organisms in which internal systems are kept in balance. Plants stay cool in the desert heat through their reflective surfaces, reduced leaves, or leaves that are parallel to the sun.
1.) Reduce the number of trips you take in your car.
2.) Reduce or eliminate fireplace and wood stove use.
3.) Avoid burning leaves, trash, and other materials.
4.) Avoid using gas-powered lawn and garden equipment.
