As for the college entrance examination, I am a candidate from Henan, and I have to do math exams, such as building a coordinate system. What pen should I use?
2B pencil is used in college entrance examination because the machine can only see the width of 2B pencil, and black pen is used in non-multiple choice questions because the machine can only see black handwriting when scanning. If you answer questions in the non-multiple choice area, you must use a black pen! ! !
(That is, 2B is used for machines and black ink pens are used for people. I just saw it. )