a question about 'agreement'

[Unregistered]

Would you tell me if this sentence is grammatically correct to the native speakers? ; 'Smoking and drinking does harm to us.'
In this sentence, is usnig 'does', a singular form-verb, correct to you or is it totally unacceptable ?
Can smoking and drinking be a semantically signle reference?
i'd appreciate your help !!!

[Tdol]

Given that they are often closely associated, the sentence sounds OK to me. However, the plural would be better, IMO, because many drink but do not smoke, and they cause different ailments.

[oldman2]

Given that they are often closely associated, the sentence sounds OK to me. However, the plural would be better, IMO, because many drink but do not drink, and they cause different ailments.

I think you mean "because many drink but do not smoke"?

[Tdol]

Thanks. I did mean that.