Answer:
All the circles are phosphates, they are the polar phosphate head. (P)
The squares (the ones that are vertical) that are linked with the cirlces are the deoxyribose sugars. (D)
the square that is linked with a is thymine (T)
the squares linked with g are cytosine (C)
Aqueduct carries water over a long distance.
The answer would be A. Methane