四期三期必开一期是什么

简介：Jierharang asked people to get a map and opened it. It was as shown on the map, pointing to a mountain ridge in the west: that is Beiling, also called Dahuailing. Although it is not high or very steep, it is It is a commanding height north of Jinzhou, but by occupying the North Ridge, cannons can be set up to bombard the post road.