Funciones de relación, el sistema nervioso y el aparato locomotor. Sociedad y Población:

are distributed across official catalogs, digital platforms, and educational repositories. While the full student textbook is typically restricted to licensed users via the Aula Virtual Santillana app, several official and community links provide access to related PDF materials like reinforcement sheets, summaries, and teacher guides. Official Santillana Resources

El cambio climático, medios acuáticos y terrestres, y la protección de la biodiversidad. El Cuerpo Humano:

: Each unit starts with a "challenge" (e.g., "Caring for our diet") to motivate students through practical investigation.