Задать 5 видов вопросов: общий, альтернативный, специальный, разделительный и вопрос к подлежащему. Для 2 предложений:
1) This condenser was used by us.
2) This work will be done by us.

This condenser was used by us.
1. Was this condenser used by us?
2. By whom was this condenser used?
3. Was this condenser used by us or by them?
4. This condenser was used by us, wasn't it?
5. What was used by us?


This work will be done by us.
1. Will this work be done by us?
2. By whom will be done this work?
3. Will this work be done by us or by her?
4. This work will be done by us, won't (=will not) it?
5. What will be done by us?