One way in which robespierre and louis xvi of france are similar is that both

Both individuals have aspects of their record which are controversial and paint each individual as a tyrant and unjust leaders. In different ways each individual is remembered for a degree of injustice that they inflicted on to the people of France as a result of their political rule. 

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.