These three idioms are all familiar to * *. But the chart is what you say to yourself; Seeing fire from the hole is observing things; If you know everything, there is no such restriction.

2. Different meanings

If you look at the fire in the hole: [interpretation] hole: thorough. As clear as watching fire? Sample. Describe observing things clearly and thoroughly.

Know everything: describe the situation clearly, will you? Like pointing to your palm, also called "? If the finger? Palm. "

A few treasures: [Yi]: the treasure of the family. Feel at home? Like jewelry. Describe being very familiar with what you say. I see.

3. Different usages

1, keep an open mind.

Usage: more formal; As predicate and attribute; If you use compliments, you usually use things that the other person hides and doesn't want people to know.

Know it like the back of your hand.

Usage: more formal; As a predicate; Know sth very well.

3, like a few treasures

Usage: verb-object type; As predicate, adverbial and complement; With praise.

References:

Baidu encyclopedia-if the hole is on fire?

Baidu Encyclopedia-Ru Ru Jia Zhen

Baidu Encyclopedia-Like the back of my hand