the new machine was used in a cave near the seashore where --it is said -- pirates used to hide gold.这里的 where -- it is said -- pirates used to hide gold是什么句式啊.写几个这样的句子

问题描述:

the new machine was used in a cave near the seashore where --it is said -- pirates used to hide gold.
这里的 where -- it is said -- pirates used to hide gold
是什么句式啊.写几个这样的句子

二位都正解~不再重复

把it is said看成插入语,where引导的定语从句来修饰the seashore
例:
I like the car that -- it is reported --is very good.

where引导的是个定语从句,两个破折号之间的是插入语.凡有两个破折号或在类似位置有两个逗号的,都可以把那两个标点和标点之间的内容去掉,理解其余部分,最后可以理解去掉的部分.
如,his father who,it is believed,was a soldier was really a policeman.