Question

los estudiantes ( estaban / estuvieron ) nerviosos antes de una prueba. estaban estuvieron

Explanation:

In Spanish, "estar" (to be) has different past tense forms. "Estaban" is the imperfect tense, used to describe ongoing or habitual states in the past. "Estuvieron" is the preterite tense, used for completed actions. The sentence describes the students' state (nervous) before a test, which is a continuous state, so "estaban" is correct.

Answer:

estaban