a wall of silence的用法和样例：
- The investigators were confronted by a wall of silence.
- But nearly a quarter of a century into the epidemic, there is a wall of silence that surrounds AIDS and same-sex practices that may prove to be a significant obstacle to conquering the disease.
- The flood came in a wall of water twelve feet high.
- a wall of silence; a wall of fog.
- They've built a wall of players for a free kick.