He hears the warning whistle like a foghorn.

他听见雾笛一样的警示信号。

When the wind is right we can hear the passing of the train itself, and the warning whistle must have come mournfully and distinctly to the Creek.

当风向合适时， 我们可以听到火车本身经过的声音， 警告汽笛一定是悲伤而清晰地传到小溪里的。