了如指掌[liǎo rú zhǐ zhǎng]
词典know ... like the palm of one's own hand：了如指掌。
词典as plain as pointing to one's hand：了如指掌。
词典be thoroughly familiar with ...：了如指掌。
词典clear like pointing at a palm：了如指掌。
词典know sth. like the palm of one's hand：了如指掌。
了如指掌[liǎo rú zhǐ zhǎng]
know ... like the palm of one's own hand; as plain as pointing to one's hand; be thoroughly familiar with ...; clear like pointing at a palm; have fully grasped a subject, a situation, etc.; have sth. at one's fingertips; know ... as a person knows his ten
例：他对这一带的地形了如指掌。
He knows the terrain of this locality like the back of his hand.
1. at one's finger's tips：at odds 争执 | at one''s finger''s tips 了如指掌 | at one''s service 随时提供服务
2. 了如指掌
2. know something like the palm / back of one's hand：pour cold water over / on 泼冷水 | know something like the palm / back of one's hand 了如指掌 | Constant dripping wears the stone 滴水穿石
3. 了如指掌是什么意思
3. know something like the palm or back of one's hand：The higher up, the greater the fall. 攀高跌重: | know something like the palm or back of one's hand 了如指掌; | constant dropping wears the stone 滴水穿石;