1. Every few hundred meters along the wall there are watchtowns, where Soldiers used to keep watch.
    沿城墙每隔几百米就有一个烽火台, 过去常有士兵驻守.

2. Everyone knows that if he shouts in the vicinity of a wall or a mountainside, an echo will come back.
    大家都知道，在墙壁或山腰附近发出的喊声，就会听到回声。

3. But in the main, I feel like a brown bag of mixed items propped up against a wall.
    但我大体上还是感觉自己像一只靠墙立着装满各种杂物的棕色皮袋子。

4. The Great Wall of China, the longest wall in the world, runs across north China like a huge dragon.
    中国的长城, 世界上最长的城墙, 象一条巨龙,逶迤在中国的北部.

5. The arrow embedded itself in the wall.
    箭牢牢地扎进墙里.

6. The wall will act as defence against flooding.
    墙能起防洪的作用。

7. The medieval town was fortified with a high wall and a deep moat.
    这座中世纪的城市用高墙深沟来加强防御。

8. The medieval town was fortified with a high wall and a deep moat.
    这座中世纪的城市用高墙深沟来加强防御。

9. There is an opening in the wall.
    墙上有个洞。

10. The ball rebounded off the wall.
    球从墙壁弹回。