According to the question material, Bernard Shaw said: "If you have an apple and I have an apple and they exchange each other, then each person has only one apple; if you have a thought and I have a thought, each other Through exchange, each of us has two thoughts, or even more than two thoughts." This shows that friendship can continuously improve and improve itself; therefore, statement D is correct and statement ABC is correct, but it has nothing to do with the meaning of the question; so choose D.