28) The study of tissue is called . 29) Secretions onto body surfaces are characteristic of glands. 30) Unspecialized epithelial cells which act as a source for mitosis are called cells. 31) The combination of fibers and ground substance in supporting connective tissues is known as . 32) are cells that are modified to transmit signals from one place to another. 33) The is the germ layer that differentiates into the GI track, bladder

because of

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.

here's your answer.

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem