1.You should try to translate the answers in whichever language you like.
2.Try to write the answer two to three times until you remember it perfectly.
3.Create short points of each sentences so you can remember them easily.
4.If the answer is related to any language subject then you should avoid remembering them instead understand the question and then answer it by your own, it will be really helpful and can decrease your stress of remembering long answer. as in higher classes remembering answers will not work!