大家都知道know是动词"知道，了解"的意思，今天我翻阅字典，无意之中，发现它还可以作名词：
（1） in the know: having more information about something than most people知情的，熟知内情的
People in the know say that interest rates will have to rise again soon.
知情人士说，利率将很快再次上升。
（2） know-how: knowledge, practical ability, or skill to do something 知识，实用技能，窍门
those who have the know-how to exploit the technology to the fullest 那些掌握了实用技能，把技术发挥到最大限度的人
No other company had the technical know-how to deal with the disaster.
其他公司都不具备应对这一灾难所必须的技术知识。
（3） know-it-all: someone who behaves as if they know everything 自以为无所不在的人
Remember, pretending to be know-it-all will bring troubles.
切记，不懂装懂会带来麻烦的。
