In geophysics the refraction or reflection of seismic waves is used for research into the structure of the Earth's interior, and man-made vibrations are often generated to investigate shallow, subsurface structures.
Flatworms are considered acoelomate, since they have no body cavity, and roundworms are pseudocoelomate because they have a body cavity, but it is not derived from the splittiâ¦ng of the mesoderm tissue. Also, flatworms only have one opening in their digestive system unlike roundworms with two.
D. flatworms. Weegy: Some type of body symmetry is found in all invertebrates EXCEPT in Sponges, answer s letter C. samn|Points 3904|User: Bilateral symmetry enables the A. division of the body into upper and lower sides. B. animal to have a right and left side. C. joining together of specialized cells into tissues.