Correct

了如指掌

/ le rú zhǐ zhǎng /
Strokes

Definition

to know sth like the back of one's hand (idiom)/to know (a person, a place etc) inside out

Example

Definition

know sb/sth like the palm/back of one's hand; know/read sb/sth like a book; have sth at one's fingertips; have a thorough knowledge (of); know thoroughly

1
Zhè
běn
jiàocái
教材
de
nèiróng
内容
  
,
lezhǐzhǎng
了如指掌
  

He is very familiar with what is in this textbook.

2
men
我们
duì
shuāngfāng
双方
de
shí
实力
lezhǐzhǎng
了如指掌
  

We know the strengths and weaknesses of both sides like the palm of our hand.

3
duì
dāng
当地
de
qíngkuàng
情况
lezhǐzhǎng
了如指掌
  

She knows the place very well.

4
duì
lezhǐzhǎng
了如指掌
  

He could read me like a book.