Final answer:
The imperfect conjugation of the verb leer for the subject Les abuelos and el periódico is leían.
Step-by-step explanation:
The correct imperfect conjugation of the verb leer for the subject Les abuelos and el periódico is leían. In Spanish, the imperfect tense is used to describe ongoing or habitual actions in the past. It is formed by adding specific endings to the stem of the verb. For the verb leer, the imperfect stem is le-, and when conjugated for the subject Les abuelos and el periódico, it becomes leían.
Learn more about Imperfect conjugation in Spanish