In his mouth were the remains of fir trees

Question

In his mouth were the remains of fir trees 这句话为什么用were啊！还有帮整理一下，are/is was/there 在一般文章中的用法，除了I'm yours, I was in there 这样的句子之外，这个基本的还是懂的， 麻烦大家了，搞不清楚， 回答好的有悬赏。

Answer 1

这是个倒装句。作者玩的不同修饰手法。正常句子词序是 The remains of fir trees were in his mouth.
are/is was/there 是 There are/is/was 的疑问句形式。