Question

Be attentive in the class. (Change the voice)

Answer 1

The correct answer is:

You are advised to be attentive in the class.

In active voice, the pronoun you is hidden while the sentence is in the form of an instruction.

The advice is given to you (student) by the teacher when the sentence is converted into passive mode.

Answer 2

Answer:

In passive voice: You are advised to be attentive in class.