简介:What Wang Si didn't see was that a large trench three feet wide and one foot deep was dug around Xiaoyuan Camp. Historically, trenches were dug in the front, back, left, and right when marching and camping to prevent enemy attacks. However, this trench was dug at Xiaoyuan Camp. The trenches were dug particularly long and wide. As usual, sharpened sticks were thrown upside down in the ditch. Once a person fell in, he would definitely die.