笛声

The din in the factory ends abruptly when the noon whistle sounds.

当中午声响起时，工厂里嘈杂声顿时停止了。

We heard the whistle of a train.

我们听到了火车声。

I heard police sirens in the distance .

我听到声从远处来。

The cars had stopped at the sound of the approaching siren.

这些车听到愈来愈声便停了下来。

In big cities you always hear sirens all the time.

在大城市里, 你总能听到声。