What process is caused by some combination of wind, water flow and gravity? a. physical weathering b. erosion c. chemical weathering d. mass wasting

 B. Erosion

Explanation:

Weathering is a process of physical disintegration of the rocks or other materials present over the earth crust into small particles or sediments due to a physical agent such as water or wind. The erosion is the process of mechanical or physical removal of the top layer of the soil or any surface material and transportation of the material to the other location. Mass wasting is the process in which unstable materials get dislocate from their place due to the effect of gravity.

Erosion is caused by the combination of physical factors like wind, water and gravity.

is this for the e2020 class

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!