Answer:
Sabrina mira por la ventana y ve que (está) nublado.
Busca su suéter favorito, que (es) de lana.
A las nueve, /está) lista y sale de su casa.
A las diez, llega a clase. Todos sus amigos (están) deprimidos por el clima.
A las 12:45, va a una reunión de estudiantes. La reunión (es) en la cafetería.
En la reunión, muchos compañeros (están) disgustados.
Explanation:
The verb ser is used in Spanish in the following situations:
physical appearance or inherent personality traits;
identity or permanent features (nationality, creed, etc);
family or personal relationships;
when or where an event takes place;
passive sentences;
with adverbs of time;
with the preposition for: recipient, objective or purpose;
the price;
the material, origin or membership of an object + preposition "de";
the profession.
The verb estar is used in Spanish in the following situations:
short-term moods or health;
appearance;
marital status;
Location;
the date or season of the year, (not the time): 1st person plural + prepositions "a / en";
modal adverbs;
states: preposition "de" + noun;
the price with the preposition "a";
way in which something has been produced;
verbal tense: estar + gerundio.
