1、对某事认识很透彻
... Was my face red! 我真是非常不好意思 know something inside out 对某事认识很透彻 sleep on it 花个一二天考虑一件事后再作决定 ...
2、了解彻底
know something inside out 了解彻底 4. know next to nothing 差不多不了解；差不多一无所知 .
3、知根知底
...In the know 知情的，消息灵通的Person in the know 知情人Know something inside out 知根知底，了如指掌 ...