定义
a wall: 墙，屏障
- "It would be lovely if there was some colour on the walls to brighten the place up a bit."
- "Hands against the wall."
- "Face the wall, bend over and touch your toes."
- "There's a poster on the wall of my office that says "A dwarf standing on the shoulders of a giant may see farther than the giant himself."
- "So many guns and trophies on the wall!"
- "I'm tired of phone calls and I'm tired of these walls."
- "knock on your door out of the blue saying that they notice that your roof / driveway / windows / walls need urgent work."
- "It also has no rats and no mouldy walls and it's in my price range."
- "Standing on the wall"
