Which of these lines from Whitman's "O Captain! My
Captain!" includes an internal
rhyme?
A. The ship is anchored safe and sound,
its voyage closed and done
B. The ship has weathered every rack, the
prize we sought is won
C. From fearful trip, the victor ship, comes
in with object won
D. This arm beneath your head;

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.