Yes it's correct, si esta correcta
Answer:
The sentence that we must complete is:
Un primo mío. Todo el mundo dice que (6) me parece mucho. Podríamos ser hermanos.
This can be translated to:
"A cousin of mine. Everybody says that he seems a lot to ___. We could be brothers"
Now, the word that completes the blank is "se"
"Todo el mundo dice que se me parece mucho"
If your asking what Educación Física It is Physics class