警察在训练时使用装有消音器的手枪以减少噪音。

The police used pistols with ___silencers during training to reduce noise.

这台发电机装了消音器后噪音小多了。

The generator is much quieter after installing a ___silencer.

新出台的法规成为了压制民间批评的声音消音器。

The new regulations served as a ___silencer for public criticism.