In this sentence, I have a little confusion about how to use time sign. Please help me, thanks!
We got in the airport to the airport 【two hours】 before our flight departed.
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I always feel as if it should be added some preposition in this sentence, like 'two hours ago', 'in two hours', etc.Sorry, I write down it wrong, original sentence:

We got to the airport two hours before our flight departed.I didn't understang why it only use 'two hours' without any other word.

and when it only use 'two hours', what meaning of this sentence is?

They had arrived at the airport two hours, or ...

Question

In this sentence, I have a little confusion about how to use time sign. Please help me, thanks!
We got  in the airport  to the airport  【two hours】 before our flight departed.
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I always feel as if it should be added some preposition in this sentence, like 'two hours ago', 'in two hours', etc.Sorry, I write down it wrong, original sentence:

We got to the airport two hours before our flight departed.I didn't understang why it only use 'two hours' without any other word.

and when it only use  'two hours', what meaning of this sentence is?

They had arrived  at the airport two hours, or ...

Answer

The sentence is correct as it is written in your "additional details". The word, "before" is used here as a conjunction, joining the two phrases together. The second phrase is describing the meaning of the "two hours", just as a prepositional phrase would do under other circumstances.

If you say, "We got to the airport in two hours.", it means that it took two hours to get to the airport. If you say "We got to the airport two hours ago.", that means two hours have passed since you arrived at the airport.

Answer

You can use an amount of time relative to some other event and with prepositions.

We got to the airport two hours before (our flight departed = upcoming event).

We left the airport one hour after (our flight landed = past event).

We got to the airport in two hours. = It took two hours to drive TO the airport.

We left the airport three hours ago. = It has been three hours since you left.

I hope that is helpful.