英语童谣中down by the station很多不懂
请问英文高手,这首童谣：
『Down By The Station』
Down by the station,early in the morning,
See the little puffer bellies all in a row.
See the engine driver pull the little handle,
“Chug,chug,toot toot!”
Off we go!
1.down by the station：是什麼意思?为什麼是『下』(down)?『by』又怎麼解释?
2.bellies是名词吗?所以是puffer bellies?指的是河豚肚子像火车?还是bellies当puffer的动词,所以加s?那See the little puffer bellies all in a row是什麼意思呢?
非常感激您的回答!