名 wall，wall of structure，sth. resembling a wall，perpendicular cliffside，cliff ；

[例句] 警方称他们像往常一样碰了壁，没人吭气。 The police say they met the usual wall of silence.

[例句] 晃动液体可以使容器壁破裂。 Sloshing liquids can rupture the walls of their containers.