Learn English – What’s the difference between “to get used to something” and “to be used to something”

Reasonable means that whatever decision was made is appropriate given the particular circumstances, and most would regard it as so.

Justified means that whatever decision was made is done for a good reason, in the interest of fairness.

There are times the words could be used interchangeably, and contexts where the difference is subtle. It all depends on the nature of the request or issue at hand.

I might use "justified" if I was angry about something, and was acting in response:

Was it polite to skip their wedding after they insulted me like that? No, but I think my decision was justified.

I might use "reasonable" if I think everyone would agree that there was nothing else that could be done:

Was I happy about missing their wedding so that I could go to my mother's funeral? No, but I think my decision was reasonable.

But there are contexts where either word will work just fine:

You said that you'd deliver the cake before noon, but it didn't get here until 3 o'clock. I think my request for a refund is reasonable/justified.

In that sentence, reasonable would work because most people would agree that a refund would be appropriate given the circumstances, and justified would work because the request is fair.

The word 'document' is a countable noun which means paper or some report. It is also as a verb ('Documentation' is not).

"The scientists documented the lab experiments to prove the herb's medicinal properties."

The word 'documentation' is an uncountable noun and is a collection of or body of material of any subject/topic.

"This is just one report, where is the documentation for the whole project?"