1 - Volcanoes are built by the accumulation of their own eruptive products, which are lava, ash flows, airborne ash and dust.

2 - After accumulating a ton of waste material, industrialists must decide where to dump it.

3 - Glaciers form when snow accumulated during the winter exceeds snow lost to melting during the summer.

4 - Although studies from earth using optical and radio telescopes had accumulated much data on the nature of spatial bodies, it was not until World War II that the development of powerful rockets made direct space exploration a technological possibility.

5 - The ice sheet that blanketed much of North America during the last glaciation was in the areas of maximum accumulation more than a mile thick.