Wasting time. It's a waste of time to answer questions, do problems and toss and turn.

After writing the questions and reading the answers, you will get into the habit of reading the answers after writing. When there is no answer in the exam, you will definitely not be used to it, and you may be flustered because there is no answer.

After writing a question and looking at the answer, you will have the urge to look at the answer urgently. When you encounter a difficult problem, you may not want to think about it, just look at the answer.

After writing the questions and reading the answers, you don't give yourself time to check, and your ability to check mistakes declines.

Of course, it is not good to write a lot and then look at the answers, and you may forget your previous thoughts.

So write about 20 questions (7 or 8 big questions are enough), and then see the answer.