Chemical weathering

a.
is caused by freezing and thawing
b.
breaks apart rocks by physical processes
c.
occurs when chemical reactions dissolve or change the minerals in rocks
d.
none of above

Average annual precipitation and are the two major features that define the biomes on earth.

Abody cell has been growing and at synthesis proteins.in the nucleus of this body cell,dna replication is taking place. and a copy of the cells genetic material is copied.which of the following is the best conclusion you can make about the life cycle of this cell ? a) the cell is ready to undergo mitosis.and a chemical signal will send the cell to prophase b)the cell is undergoing meiosis and will cross over the genetic material next c)the cell is in the s phase of interphase and will move next to the g2 phase d) the cell is in the g2 phase of the interphase and is ready to begin diving

Substances that can pass through cell membranes by diffusion include a. na ions. b. proteins c. glucose. d. oxygen.