The answer is...
Mis primos creen en Santa Claus.
Hope it helps!!
Answer:
you (s) train ⇒ tú entrenas, usted entrena
you (pl) train ⇒ ustedes entrenan
they train ⇒ ellas entrenan, ellos entrenan
he trains ⇒ él entrena
Your answer will be
Estacionar
Which basically mean park
B. busco
It can't be Busca, buscamos is like a group looking, Buscas is like someone else looking. So it's ..Yo Busco