Final answer:
The word that completes the phrase 'necesita llamar al hospital' is 'Alguien' (someone).
Step-by-step explanation:
The word that best completes the phrase 'necesita llamar al hospital' is Alguien, which translates to 'someone' in English.
When someone needs to call the hospital, they usually call a person (alguien) who can help them.
The other options - Algo (something), Nada (nothing), and Siempre (always) - do not fit the context of calling the hospital.
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