is there a sentence fragment? even though rainbows often appear to contain a band of purple. its just an…

is there a sentence fragment? even though rainbows often appear to contain a band of purple. its just an optical illusion. yes no
Answer
Brief Explanations:
The first part "Even though rainbows often appear to contain a band of purple." is a dependent - clause and cannot stand alone as a complete sentence. It lacks a main clause to complete its thought.
Answer:
yes