fortress
单词辨析：
指古代为了防御敌人进攻而修建的庞大而坚固的建筑物。
Visitors to the castle are asked not to take photographs.
来城堡参观者不得拍照。
Most castles were built on hilltops.
多数城堡建在山顶上。
指在重要之地修建的建筑物或建筑群，常围有高墙，用于屯兵守卫。
There are many forts on the coastline.
海岸线上有许多要塞。
The attack succeeded, and the fort was taken.
袭击成功，拿下了堡垒。
指比 fort 大的堡垒，用于防御。
Our soldiers took over the fortress.
我们的士兵占领了那个要塞。
The easiest way to capture a fortress is from within.
堡垒最容易从内部攻破。
相关例句：
The fortress is only half open.
毕竟堡垒的大门只敞开了一半。
Our soldiers laid siege to the enemy fortress.
我们的战士包围了敌人的堡垒。
China, for the Great Wall and from Peru for Machu Picchu, the fortress city of the Incas.
长城的祖国中国和印加要塞马丘比丘的祖国秘鲁。
The army retreated from the ruined fortress.
军队撤离了倒毁的堡垒。
The general hastened to the relief of the fortress.
将军火速前往救援该要塞。
This is an impregnable fortress.
这个堡垒是攻不破的。