It is ten years ago (that) I came to this town.
问题描述:
It is ten years ago (that) I came to this town.
答
It 是形式主语,真正的主语是that后面的 I came to this town,也就是这句话换做正常语句的话就是
I came to this town ten years ago.10年前我来过这个镇.