Answer:A U G C G C A C G U G C U A C G U C A U C A U G
Explanation:
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.
The best option is D. Based on scientific evidence about algal bloom, it would be best to evacuate all humans from the area around the lake. Algal bloom is caused by excess nutrients in the lake. This occurrence is linked to the death of fishes, plants, mammals and birds. Also. it has been said to cause human illnesses. Thus, to avoid this, it would be best to stay away from the lake with algal bloom.
The answer is because biology is easy and they're known around the world.
