What process caused the accumulation of sand that produce the sand dunes? A. deposition
B. physical weathering
C.
chemical weathering
D.
erosion

pure substance: iron,copper

impure substance: water,charcoal

plants need sunlight, water, and carbon dioxide to make food. plants use the raw materials of water, nutrients they absorb from soil, and carbon dioxide to make sugars the plant can use. energy from the sun and chlorophyll are also needed.

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?