Irish comprehensions can be hard to answer and most students copy straight from the text. However, doing this, especially on HL will only get you a few marks - maybe not even half the marks for each question that you give this type of answer to - even if it's correct! You MUST refer back to the question.
What I do, is I first add the article "an" to the sentence and the thing that the question is asking me for - example, fáth (reason). So I write down "an fáth" - the reason and then copy the rest of the question and at the end of that write down "ná" and copy your answer from the text! Therefore, this way, you are not copying EVERYTHING from the text - some of it and you're referring back to the question. This way, you get your full marks easily.
However, if it says pronouns like "muid/sinn" or "againn" or "orainn" etc, change it to "siad, acu, orthu" etc.
Just copy it from the text, you do actually get full marks. I got full marks in the mocks and I just copied the text, I didn't even know what I was writing about. Just find the sentence with the same words and write it as the answer. The only time you would change anything would be if its it the first person ie just change mé to sí, agam to aici etc