Контрольную пломбу поставили, и ячейку для хранения опечатали.

Not here. Пломба can mean a dental filling, but in this sentence it means a seal, especially a security seal or tamper seal.

So контрольная пломба is something like an inspection seal, control seal, or tamper-evident seal placed to show whether something has been opened or interfered with.

The meaning depends completely on context:

• зубная пломба = a dental filling
• контрольная пломба = a security/control seal

Because контрольную пломбу is the direct object of the verb поставили.

The base form is:

• контрольная пломба = nominative singular

But after a transitive verb like поставить when it means to place / apply, the object goes into the accusative:

• поставили что? → контрольную пломбу

Both words change because the adjective must agree with the noun:

• контрольная → контрольную
• пломба → пломбу

Literally, поставить often means to put, to place, or to set. But in this sentence it is used idiomatically.

With пломба, поставить means:

• to place a seal
• to affix a seal
• to apply a seal

So it is not just a casual put. It sounds like an official action.

This is very common in Russian: a general verb like поставить can have a more specialized meaning depending on the noun that follows.

This is a very common Russian pattern. A 3rd person plural past verb can be used when the people who did the action are unknown, unimportant, or left unspecified.

So:

• поставили
• опечатали

does not necessarily mean a clearly identified they. It often means something like:

• they did it
• someone did it
• the staff / officials did it

In English, this is often translated more naturally with a passive:

• A control seal was placed...
• The storage compartment was sealed...

Russian often prefers this active-looking structure with an omitted agent.

They are related, but not identical.

• поставили пломбу = they attached/applied a seal
• опечатали = they sealed something officially, often so it cannot be opened without evidence of tampering

Опечатать comes from печать, meaning seal or stamp in the official sense.

So the sentence describes two separate actions:

1. A control seal was applied.
2. The storage compartment was officially sealed.

In practice, both actions are about security and preventing unauthorized opening, but the verbs focus on different things:

• поставить пломбу focuses on the seal itself
• опечатать focuses on securing the whole object

Ячейку is the direct object of опечатали, so it is in the accusative.

The phrase для хранения means for storage or for keeping things.

Here:

• для takes the genitive
• хранение is a noun meaning storage, keeping, or safekeeping
• after для, it becomes хранения

So:

• ячейка = a compartment / cell / storage box
• ячейка для хранения = a storage compartment / storage locker / deposit box, depending on context

Both verbs are in the perfective past:

• поставили < поставить
• опечатали < опечатать

Perfective is used because the sentence presents these actions as completed results:

• the seal was placed
• the compartment was sealed

This fits the situation well, because the sentence is reporting finished official actions.

If imperfective were used instead, it would suggest something more like:

• an ongoing process
• repeated action
• background description

But here the point is the completed outcome.

Russian word order is flexible, and the beginning of the sentence often shows what the speaker wants to focus on first.

Starting with Контрольную пломбу gives the sentence a slightly more report-like or official feel. It foregrounds the object/result.

A more neutral alternative would be:

• Поставили контрольную пломбу, и опечатали ячейку для хранения.

That is also possible, but the original version is perfectly natural.

So the object-first order here is not strange; it is just a matter of emphasis and style.

Yes. A passive version would be something like:

• Контрольная пломба была поставлена, и ячейка для хранения была опечатана.

This is grammatical, but it often sounds a bit heavier or more formal.

In Russian, the version with omitted agent and plural verbs:

• поставили
• опечатали

is often more natural than a full passive, especially in reports, narratives, or procedural descriptions.

So both are possible, but the original structure is very typical Russian.

Yes, it sounds fairly official, procedural, or administrative.

Words and phrases like:

• контрольная пломба
• ячейка для хранения
• опечатали

belong to a register you might expect in:

• security procedures
• inventory records
• inspections
• official reports
• legal or administrative contexts

A native speaker would not usually use this kind of sentence in casual everyday conversation unless they were specifically talking about a formal security process.