The bunch of flowers (has, have) faded although i put (it, them) in water the moment (it, they) were cut.
We have complained to the Health Department about it but so far (it, they ) (hasn't haven't) done anything about it.
The management (does, do) (its, their) best to help the workers.
In my opinion, i will use plural for number 1, singular for number 2, and singular for number 3. Though understanding that agreement for collective noun as such should be assessed by looking at the context of the subject, i m still confused, especially on how to explain them to my students. Could somebody teach me how to determine the answers for the above questions. Thank you.