警笛

The policeman whistled for the motorcar to stop.

警察吹警笛令汽车停下。

I heard the wail of a police siren.

我听见警笛的尖叫。

I heard police sirens in the distance .

我听到警笛从远处传。

In big cities you always hear sirens all the time.

在大, 你总能听到警笛。

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

这些汽车听到的警笛便停了下。

When he heard the police sirens, he ran off as fast as his legs could carry him.

听到警笛响起，他拚命地跑。