I have written both compulsory questions and one-off questions, and the amount of the two questions is similar. However, the quality of the required questions is higher and the application of knowledge points is more flexible. The more basic the question is, the more difficult it is to get to the back, and the layers are progressive. There are also questions that must be brushed, and exams often have the same result.
First of all, it looks good to write on the paper that must be brushed! This is a very important point. Sometimes writing extra-curricular questions with particularly bad paper will make you feel inexplicably upset and can't write any more. But the paper that must be brushed, v5 is written in one word, cool! There is also the category of mandatory questions that I like very much.
Every time you find that you have not mastered a certain knowledge point in the exam, it is an explosion to open the required questions! Follow the catalogue and easily find the place you want to train. Finally, the topic that must be brushed is better.
There are no topics that are too difficult or too biased. If you can't do it, you can do simple questions to find the state. When the state comes, you can do some intermediate questions to exercise yourself. Of course, there will be more difficult questions, but there will never be too biased questions, which makes me like to brush the questions.