it is believe that the huge cave was discovered

y accident

该句要表达的意思:据说这个巨大的岩洞是偶然被发现的。
英文表达:It is believed that the huge cave was discovered by accident.
It is said that the huge cave was discovered by accident.
解释:这是由it作形式主语引导的从句。真正的主语是the huge cave was discovered by accident,所以这件事情是被相信的,所以要用被动式。
It is said that 据说 是一个固定搭配
by accident 偶然 是一个固定短语
希望能帮到你。
温馨提示:答案为网友推荐,仅供参考