What mechanical waves needs a medium to travel through?

a. all mechanical waves need a medium to travel through
b. surface waves only
c. transverse and longitudinal waves only
d. longitudinal and surface waves only

Which function is performed by earths atmosphere? a. ultraviolet rays are prevented from reaching the ozone layer. b. earths temperature is raised and moderated by trapping in heat c. charged particles from the sun are prevented from reaching earth. d. magnetic charges from space are prevented from reaching earths surface.

What are fructose and glucose an example of?

How can a give a full method for the experiment of separating sand from water by filtration? 1-materials 2-steps 3-conclusion also for water and salt separated by the evaporation or distillation process