Her letter seemed pretty cheerful, but if you read between the lines, you can tell that she's not really happy.从她的来信看，似乎她相当开心，但从字里行间你可以看出她并不是真的快乐。Some kinds of poetry make you read between the lines.有些诗要你从字里行间去体会其含意。Perseverance is required to understand the story and you have to read between the lines to find the book's full meaning.要读懂这个故事需要锲而不舍的精神，而想彻底弄懂此书的含义则需要领会言外之意。