09 Niu PubMed Mathematics Two Difficulties. I just read the posts posted by everyone and said it was difficult to count one. I took the second test. Compared with before, I think it is much more difficult to choose the multiple-choice questions in the number two exam this year, and the big questions in linear algebra are also difficult. Although it is easier to think of big questions with high numbers, the amount of calculation has increased. On the whole, I think it is still a little difficult to count two.