steam lap

例句：

1. 1. The train's steam whistle blew as it approachedthe station.
   火车的蒸汽哨子在接近车站时吹响了。
2. 2. The engineerwas busy checking the steam pressure on thelocomotives.
   工程师忙于检查机车上的蒸汽压力。
3. 3. The steam-powered locomotives were used to transport goodsacross the country.
   蒸汽动力机车被用来将货物从国内运输到国外。