2 then 1 then 3 you're welcome
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).
In the cross-section of a kidney, there are three main regions that become apparent. The outer region is called the "renal cortex", this is where the capillaries are mainly located. The deeper and darker region, that looks like small pyramids arranged in a semicircle is called the "renal medulla", where the filtering of the blood takes place. The flat, tube-like structure is called the "renal pelvis".
The phylum of Psychedelic Sea Slugs is Mollusca.
