Final answer:
The appropriate verb to fill in the blank is 'está'. This verb is used to indicate a temporary state or condition. Examples of when to use 'está' would be 'Estoy cansado' (I am tired) or 'El perro está jugando' (The dog is playing).
Step-by-step explanation:
The appropriate verb to fill in the blank in the sentence is está.
Juanita está preocupada porque tiene un examen hoy.
This verb is used to indicate a temporary state or condition, and in this sentence, it is expressing Juanita's temporary state of being worried. Some examples of when to use está would be "Estoy cansado" (I am tired) or "El perro está jugando" (The dog is playing).
Learn more about Verb usage in Spanish