my motto in life is that:"books are the ladder of human enlightenment"
或
my life motto is that: "books are the ladder towards human enlightenment"
my motto in life is that books are the ladder of human improvement (这是直接翻译的, 但是 这样用英文很 不好。进步不能直接翻译成英文。 )
我中文不很好。
The adage of my life is 'Book is a ladder for the advancement of human'.