It depend some plants have the waxy layer because of their cuticles and to make sure the leaf doesn't dry out or to protect it againts the harmful sun rays when directly shined on its good to have sun but not too much. HOPE THIS HELPS
Answer:
<h2>pulmonary trunk</h2>
Explanation:
The pulmonary valve is an important semilunar valve and found in the heart between the pulmonary artery and the right ventricle. This valve contains three cups that are responsible for the guarding of the pulmonary trunk. The pulmonary trunk is an important vessel of the heart that arises from the right ventricle and plays an important role in the circulation of the deoxygenated blood. The pulmonary trunk is called the main pulmonary artery.
The continental shelf is a gently sloping feature found at the edge of a continental landmass going seaward from the coast. Rivers that empty into the sea can produce currents that are strong enough to erode the material that builds the shelf. When this occurs channels or submarine canyons are formed. These canyons are deep and dark as no light can penetrate these regions. The canyons often lead out to sea towards the edge of the shelf.
