Question

complete the sentence.
_________________________ music for the glass armonica, but he also
invented the instrument itself.
benjamin franklin composed not
only
not only did benjamin franklin
compose

Explanation:

To complete the sentence, we analyze the structure. The phrase "not only...but also" is used for parallelism. The second part has "he also invented", so the first part should have a structure that pairs with it. The option "Not only did Benjamin Franklin compose" uses inversion (common with "not only" at the start of a clause) and fits the "not only...but also" structure, where "compose" pairs with "invented" in terms of verb form and the clause structure. The other option would not create a correct parallel structure with "but he also invented".

Answer:

Not only did Benjamin Franklin compose