THESIS STATEMENT就是中心句,文章给出的例子和内容都要围绕THESIS 的意思写。楼主的句子可以做THESIS,只要楼主写的都是他的PARTICULAR FORCE怎么让他变成一个技艺精湛的摄影师就OKAY啦。INTRODUCTORY STATEMENT是把读者引入文章的句子,不一定要和文章中心意思相干,如The art of photography is a modern art, but it does not lack the many virtuosos as oil painting and sculpting in ancient times.