Question

we can not undo what we do .(voice change)

Answer 1

What we do cannot be undode by us.

Answer 2

Answer:

What we do cannot be undone by us.

Upon changing the voice of the given sentence, we cannot undo what we do.

The sentence will be as follows what we do cannot be undone by us.

You can discuss the same with your teacher regarding the voice changing, as there is active voice and passive voice to have a better understanding.