Answer:
Permafrost areas have very cold air temperatures, thin topsoil, and most water is frozen during the winter. ... Tundra is found at high latitudes and at high altitudes, where the permafrost has a very thin active layer. The active layer of tundra is too thin for trees to grow, because it cannot support a tree's roots.
The correct answer among the choices provided is option A. Lung capillaries are responsible for exchanging carbon dioxide for oxygen from the air. Blood that comes from the heart gets oxygen from the alveoli. The carbon dioxide in the blood goes into the alveoli at the same time.
<span>At the base of Arthropoda.</span>
Answer:
because plants faces and gets sunlight to grow
