这个句子是什么结构？

宾补结构
First I heard a noise,which sounded like a train "going" under my house.
此句中主干句中主语是I ，谓语是heard，宾语是noise。
which sounded like a train "going" under my house这句是宾语从句，这个句子的主语就是 noise谓语是sounded，而going" 是非谓语表示一种状态。

宾补结构

宾补结构 going在这里修饰 a train这个宾语
要加谓语动词的话就要再加个主语that
First I heard a noise,which sounded like a train "that was going" under my house.
构成一个定语从句

宾语补足语
动名词可以做宾补 不缺谓语不用再加

句子之间的几个结构我真的分不清,这个going起修饰作用,是个壮语的形式,用来形容火车的状态.

宾补结构啊