Which of the following statements is true? a. groundwater doesn't exist in dry climates. b. fifty percent of earth's freshwater is underground. c. soil with mixed particles of different sizes is very porous. d. groundwater adds water to lakes, rivers, and oceans.

the correct answer is in fact D- groundwater adds water to lakes, rivers, and oceans :)

Option D, groundwater adds water to lakes, rivers, and oceans, is the right answer.

Water held under the ground in the earth or in vesicles and cracks in the rock is known as the ground-water. Alternatively, the groundwater is the water found under the surface of the earth and in the clefts of rock deposits. The groundwater is usually less expensive, more accessible and less exposed to con-tamination than outside water. Therefore, it is used to meeting the need for public water supplies. Moreover, the groundwater adds water to lakes, rivers, and oceans, which becomes accessible to rural people and other living beings.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.