C22 Train Power Technology Problem

Just as Zhang Hong, Zhao Cheng, and Zhang Yu implemented the education plan, as a technical school student, Su Jianguo was still working hard on the homework that Zhao Cheng arranged: researching the Xin Gan line train.

On the study desk in the dormitory, Su Jianguo placed dozens of hand-drawn blueprints. Each blueprint had complex data and calculation formulas.

Along with these calculations