There are two main reasons why cells divide rather than continuing to grow larger and larger: ... more demands the cell places on its DNA. If the cell grows too large, it will have trouble moving enough nutrients and wastes across the cell membrane.
There are 2 high tides and 2 low tides every 24 hours.
H2+1/2O2-->H2O
since there are two atoms of hydrogen present in the reactants and in the product you don't need to add any number before H2
we add 1/2 before O2 because only 1 atom is needed for the water molecule
A, the others are unrealistic speeds.