Pasiva. Explicación y ejercicios.

http://curso-gratis-ingles.euroresidentes.com/2006/05/la-pasiva-en-ingles-passive.html

http://www.ejerciciosinglesonline.com/exercises-and-theory/ex1-passive/

http://www.ejerciciosinglesonline.com/exercises-and-theory/ex2-passive/

http://www.ejerciciosinglesonline.com/exercises-and-theory/ex3-passive/

https://www.ejerciciosinglesonline.com/pasiveexercise7/