While there are signs that a mushroom is poisonous, they are not consistent, and all mushrooms of unknown origin should be considered dangerous to eat.

尽管有特征说明蘑菇是有毒的，但它们是不一致的，所有来历不明的蘑菇都应该被认为是有危险的食物。

This truck is of unknown origin.

这辆卡车来历不明。

The truck is of unknown origin.

这辆卡车来历不明。

TANGIBLE COMMON EQUITY, n., unknown origin.

有形普通股权益(TANGIBLE COMMON EQUITY)，名词，起源未知。

He told me it was a word of unknown origin.

什么…_百度知道他告诉我这是一个不知道来历的单词…