参考例子
1.Both the outer and inner parapets are
crenellated
with merlons, so that shots could be fired at the enemy on both sides, a feature very rare on other parts of the Great Wall.
在墙顶上内外两侧都有建有矮墙垛口，可两面拒敌，这一特征在其他长城的其他部分里是很罕见的。