The rigth answer is D.
The wavefront or wavefront is an equal phase surface of a wave, i.e., these points have the same travel time from the source. The concept is used to describe the propagation of waves such as sound or electromagnetic radiation (light, radio waves, etc.). In a homogeneous and isotropic medium, in which the waves propagate without deformation, two types of particular waves are distinguished according to whether the wavefronts are spheres (spherical wave) or planes (plane wave).
Answer: Single cell organisms dont need a respiratory system because oxygen and carbon-dioxe diffuses between their body tissues and the enviorment.
Answer:Scientists have long believed that the 14 species of finches on the Galapagos Islands evolved from a single species of finch that migrated to the islands one to five million years ago (Lack, 1940).
Explanation:
I think the answer you're looking for in theory but I could be not understanding the question well enough.
Both of them are a wet, damp environment!
Have nice day!
:D