翻译成英文：元曲和唐诗宋词鼎足并举,成为我国文学史上三座重要的里程碑.

Yuan qu,Tang shi and Song ci,which were variety types of classical Chinese poetry form originating from Yuan Dynasty,Song Dynasty and Tang Dynasty respectively,had emerged and played as a well-established tripod-like invaluable roles along the course of Chinese culture,and inevitably turned themselves into three significant milestones in the history of Chinese literature.