四则混合运算指的是哪四个

简介：In this way, the Ming army successfully completed the encirclement of Jianlu. The Jianlu who crossed the river were surrounded by the river bank, which was less than a thousand steps long and six hundred steps thick, forming a square formation. Because of the place It was so small that the Jianlu troops seemed very crowded, and they lost the space to dodge and maneuver.