The answer is fiesta. Because fiesta is party, the full sentence is English is “Santiago Birthday party is Saturday”
Spanish: En los años 1800s, Gran Bretaña y los Estados Unidos tenian leyes encontra de unirse mayormente porque creían en la unidad.
A mi tambien desde de pequeno me gusto jugar XD
The answer is este it is used as a masculine adjective where as esto is a demonstrative pronoun for masculine and feminine nouns