5. The students must answer a lot of questions. A lot of questions ______ by the students.

Решение:

Для преобразования в пассивный залог, ставим объект действия (a lot of questions) в начало предложения и используем модальный глагол "must" с "be" и причастием прошедшего времени.

1. A lot of questions must be answered by the students.

Ответ: A lot of questions must be answered by the students.