看不出(问题所在);说不出(差别)
not put your finger on sth
看不出(问题所在);说不出(差别)
to not be able to identify what is wrong or different about a particular situation
There was something odd about him but I couldn't put my finger on it.他有些古怪,但我说不出到底是什么。
释义来自《牛津高阶英汉双解词典》第 9 版