Its Fins, gills, and tail are all crucial for a sharks survival
Explanation:
The Nebular hypothesis is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System (as well as other planetary systems). It suggests that the Solar System formed from gas and dust orbiting the Sun. The theory was developed by Immanuel Kant and published in his Allgemeine Naturgeschichte und Theorie des Himmels ("Universal Natural History and Theory of the Heavens"), published in 1755 and then modified in 1796 by Pierre Laplace.
The solar nebular hypothesis describes the formation of our solar system from a nebula cloud made from a collection of dust and gas. It is believed that the sun, planets, moons, and asteroids were formed around the same time around 4.5 billion years ago from a nebula.
C: rainforest are biologically more diverse than ecosystems.
Explanation: the reason why this is correct is because of the vast ratio of American and Europeans animal/plant species compared to Brazil alone. They have much more diversity hence having more biodiversity. The vast amount of plants and animals are superior to other countries.
The answer is artery.
A blood vessel with a thick layer of smooth muscle and elastic fibers is artery. Even though both artery and veins are smooth muscle and elastic fiber. The difference is veins have valves, while arteries don't.