How do rivers erode Earth's surface?

A. Rivers experience extreme temperature changes, causing rocks to contract and crack.

B. Rivers do not cause any changes to surface rock or underwater rocks as they move over them.

C. Rivers remove plants from their bottoms and deposit them downstream, leaving rocks
unaffected.

D. Rivers break small pieces of rock from their sides and bottom and deposit them downstream.

the answer is "a.) well–developed vascular system."

explanation:

i thinking chemical change

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation:

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation: