Youll never plow a field by turning it over in your mind

Spending your time too long thinking about your course of action will never get the action done. Get up and do the thing instead of just pondering it forever. Take action.

Okay, biology isn't exactly my strongest subject (it never has been), but i'm pretty sure the answer is nucleotides. dna is made up of nucleotides. each nucleotide contains a phosphate group, a sugar group, and a nitrogen base. there are four different nitrogen bases: adenine (a), thymine (t), guanine (g), and cytosine (c). a always pairs with t, and g always pairs with c.