Modal verbs with passive

Why ... he take the blame on himself? It's not fair.

We ... have watched this film before, it has not just been released.

There was no furniture in the room, so a table and two chairs ... to be brought.

The decline in quality of services __________ by the experts.

Measures should ____________ to avoid such a problem in future.

This situation is serious. Something must ......... before it's too late.