The base of the pyramid is built from organisms that primarily a) are autotrophs. b) are heterotrophs. c) consume organisms located above them.

The base of the pyramid is built from organisms that primarily are autographs. A

compost can be added to topsoil as a:

pesticide

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

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