Question

这句英语的语法结构

They could hear an insistent booming sound 【which】 they found was caused by a small water-spout shooting down into a pool from the roof of the cave.
句子which引到定语从句，修饰sound吧？如果是，那么they found 又引到了一个宾语从句，that省略了。如果是这样，主句已经说They could hear ，从句又加个they found不是多余吗？，可以不需要they found.

总之，请帮忙分析下好了 谢谢

Answer 1

个人认为楼主的问题问的不太清晰。其实我不太理解什么叫they found是多余的？这个句子的主句是they could hear an insistent booming sound后面的从句是修饰sound的。所以后面的定从可以paraphrase成they found a sound that was caunsed by a....
主句陈述的是他们听到声音的事实，定从介绍说明这声音的来源，他们发现这声音是有……引起的。两者并不冲突。比如，我听到一声巨响，然后我发现这声巨响是由打雷引起的。

Answer 2

they found省略当然可以，也不影响句子，但你认为多余也值得商榷。举一通俗例子。“我听见歌声，我发现歌声是从某地传来的或我发现歌声是某人唱的。”你的说“听见，发现”重复了吗？
欢迎探讨！共同进步！
赞同请采纳！

Answer 3

但从语义上讲也不重复，hear 是一个结果，found 是一个原因，这里的found 不是听到的意思，而是探寻。就是：他们听到一个声音，经过探寻发现是.......原因。

Answer 4

答：查此句来自：TPO 听力原文(10)，但我怀疑是听力稿，因为有很多不合句法的句子。请提供录音链接，让我们听听，到底说的是什么？
摘两段 如下：
Student
Well, yeah, I can see that. I think though I have always been able to stay pretty true to what I want to create, not what others want me to create. I think that comes through my work.

Professor
Ok, just remember that is one thing to create works that you really want to create one that in the classroom. The only thing is stake is your grade. But what create outside the classroom? That could be in different story. Eh, I’m not talking about techniques or things like that. It’s just there is so much more stake when you are out there making art for living. There are a lot of
pressures to become something you are not, and people often surrendered to that pressure.
经对比，发现你的句子比我摘的句子还要准确些，所以我判断，这是不准确的听力稿。
你的也有可能是不准确的。
原句很可能是：
just remember that it is one thing to create works that you really want to create when it’s in a classroom.
就是少听写了that 宾语从句中的一个形式主语it ,真正的主语是不定式to create works, 后面的这个that-从句是定语从句。 when-是时间状语从句。
译：请记住：在教室里创作你真正想要创作的作品是一回事。

Answer 5

they found 是定语从句里的类似于ithink ,i believe 的插入语，可以有，如果没有，也不影响语义。如 I rent a flat which i think is the most cheap one. 如果没有ithink ,语义不受影响，但是没表达出我认为。这句话也一样，如果没有they found, 没表达出他们发现。