9. Mientras Enrique _C. tocaba
_ la guitarra, Carmen cantaba.
11. San Sebastian sits on B. the Bay of Biscay.
12. Juan Tomas Avila Laurel went on a hunger strike to protest A. the presidents regime in Equatorial Guinea
19. Yo _D. compré_ in libro y despues fui a casa.
It is not C. compró because I just took a test that has that same exact question and I put down C. compró and I got it wrong. So I thinks it's D. compré.
because conocer is used more when you personally know someone/thing
saber is used when you know facts about someone or something.
se is conjugated in the yo form
sabes is conjugated in the tu form so this one is correct because you are asking someone if they know where the party is.
Did you spell it correctly ?