Balancing equations
nahco3 = na2co3 + co2 + h2o

its first and third is your answer i did the qustion the fourth isnt right

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? ?