not knowing something that you should know or need to know: ______
举一反三
- If you know the ( )of something, you know all the
- You should keep those old bottles --you never know ______ you might need them.
- In a job interview, you should make every ___________ to show that you know something about the structure of the company.
- If you know the of something, you know all the details about it and understand how it works.
- I don't know when you happened______the news, but I hope you can keep it secret. A: knowing B: to know C: known D: to be knowing