Guide to solving problems in junior middle school physics/gold medal road race, edited by Peng Dabin, Shaanxi Normal University Press.

Relatively high cost performance

This is a famous brand competition instructor. "High School" was compiled by Zhang Datong. Why are they all big?

But apart from math and information, I personally think junior high school competition is not difficult. I was not prepared at that time and won the first prize in natural science.