Some cicada species are known as locusts or harvest flies. which of these words or phrases is the complete subject?
a. locusts or harvest flies
b. species
c. are known as locusts or harvest flies
d. some cicada species.

A subject in the sentence refers to who performs an action. Whereas, a complete subject is also the simple subject or main word in a sentence which may have a modifier to describe it.

To identify a complete subject in the sentence, it answers to the question of "Who performs the action?" or "What performs the action?" A complete subject includes the subject and the words which modify it.

Therefore, in the above sentence, a complete subject is "Some cicada species." Herein, the subject is cicada species and the word which modify the subject is "Some."

it would be d cause refers into the pargrapgh

might need to ask questions people no or have read somthing about.