Have a look at these links. They will introduce you to the passive voice and causative passive constructions with exercises and answer key.

THE PASSIVE VOICE-Theory and Practice -Upper Intermediate andAdvanced

Recommended exercises for those who still need more practise on passive:

Passive exercises worksheet-Intermediate

and its key: Passive exercises worksheet- Intermediate_KEY


Making questions

Here you can find all you need to know about questions. Types and differences and lots of … exercises.

Upper-Intermediate and Advanced question theory

Making questions exercises_Mixed types

Making questions exercises_Mixed types_KEY