One scientic knowledge that I think it is important is “psychology.”  It helps teachers to communicate with students by their hearts through which they won’t feel  alienated to each other.  What does psychology give me, other than 6 beautiful years of studying life?  Many things that I want to pass on to my friends:  Know how to communicate with others by what Wordsworth said “sympathetic imagination.”  Never judge people by their single outer behavior.  Have a sensitive heart to help people in need.  And so I have patience to all my students who like to study in my class, whether they had talent or not.  And I also learn a lot from them.