static amplifier

例句：

1. 1.The room is completely silent; there's no sound at all.
   房间完全静悄悄的，一点声音都没有。
2. 2. The car is stationary on the road.
   汽车停在路上。
3. 3. The robot is static and doesn't move.
   机器人是静止的，不会移动。