If you have two objects with exactly the same dictionary words associated with them–that is, the words that can be understood as those objects–then Inform treats them as identical and doesn’t try to do disambiguation for them. There’s some discussion of that here.
There’s no way to interact with different ones in this case because, well, there’s no way to interact with different ones! Anything the player types could be understood as any of those objects. There are a couple of edge cases where this causes issues–if you’ve got an Understand by relations statement, Inform won’t realize that this is a possible way of distinguishing the two objects, and will treat them as duplicates. For instance:
Lab is a room.
A rock is a kind of thing.
Understand "on [something related by reversed support]" as a thing.
The counter is in the Lab. One rock is on the counter.
The table is in the Lab. One rock is on the table.
After printing the name of a rock (called stone) when the stone is on a supporter (called the pedestal): say " on [the pedestal]".
Ideally if you said “x rock” the game would ask “Which rock do you mean, the rock on the counter or the rock on the table?” But the parser isn’t quite clever enough to figure out that it can do that, so it automatically selects one.
You can, however, understand things by their properties, and the game will know that those aren’t indistinguishable:
The servant's living quarters is a room.
A servant bed is a kind of enterable container. The printed plural name of servant bed is "servant beds". There are 10 servant beds in the Servant's living quarters.
A servant bed has a number called id. Understand the id property as referring to a servant bed.
After printing the name of a servant bed: say " [id of the item described]".
When play begins:
let index be 1;
repeat with cot running through servant beds in the servant's living quarters:
now the id of cot is the index;
increment the index.
This code assigns different IDs to the servant beds and lets the player refer to the beds using the IDs (they also have to type “bed”–the “referring” in the Understand statement means that the property can’t be the only thing the player types to refer to it, if you want to let that happen you’d say “describing”). It has lots of design problems, as you can see if you look at the room description, but it shows one way you can let the player interact with specific duplicate objects.
Another way is simply to give the different beds names, so they aren’t duplicates:
The servant’s living quarters is a room.
A servant bed is a kind of enterable container. The printed plural name of servant bed is "servant beds".
The messy bed is a servant bed in the living quarters.
The rumpled bed is a servant bed in the living quarters.
The shipshape bed is a servant bed in the living quarters.
And finally it’s worth asking yourself whether having ten actually-implemented identical beds is really necessary for your gameplay.