Which two spheres interact to produce waves and currents?

Which box will not accelerate? 4 newtons 4 newtons 4 newtons 25 kg 4 newtons 15 newtons 10 kg 30 newtons 40 newtons 50 kg 30 newtons 30 newtons

What type of appendages do sponges cnidarians roundworms annelids mollusks arthropods echinoderms and vertebrate have? jointed, not jointed, absent  

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere