了如指掌用英语怎么说

know sth. like the palm of one's hand

back of sb's hand

I can read it like the back of my hand.我可以倒背如流

know sth like the palm of one's hand/
know like a book/
have sth at one's fingertips

以上是"了如指掌"的英语表达

例句:
He had the whole design of the machine at his fingertips.他对这种机器的整个设计了如指掌

参考资料：汉英成语字典