not know from nothing

• 全然不知；毫无所知

not know from nothing的用法和样例：

例句

1. He's not altogether sure what to do.
   他全然不知该怎么做。
2. Cocooned in luxury, sheltered from reality, they don't know what travelling is all about.
   他们享受舒适豪华，与现实世界隔绝，全然不知旅行的真谛何在。
3. I do not know the first thing about software.
   我对计算机软件毫无所知。
4. We know nothing about the financial affairs of the firm mention in your letter.
   我们对贵方来函中所提及公司的财务状况毫无所知。