请将下面这段话翻译成英文：
宋词(Song Ci)是古代诗歌的一种，可以配乐歌唱，又称曲子词。因为宋词句子长短不一，所以又称“长短句(Changduanju)”。词有各种曲调，因此演唱方式多种多样。词在宋朝达到鼎盛时期。和唐诗一样，宋词在中国文学史上占有重要地位。在词的发展过程中，涌现出很多杰出的词人，如苏轼、李清照、辛弃疾、陆游等。如今宋词仍然很受欢迎。《宋词三百首》(Three Hundred Song Ci Poems)一书非常流行，很多著名的词作都被重新谱曲演唱。
参考翻译
Song Ci is one form of ancient poetry and can be sung to music，thus it's also called musical Ci poetry.Since the length of the lines in a Ci poem can vary, it is also called Changduanju (lines of irregular lengths).Due to various tunes used for them, Ci poems can be sung in different ways.Ci poetry reached its peak during the Song Dynasty.Like Tang poetry, Song Ci poetry plays an important role in the history of Chinese literature as well.In the process of its development,a lot of prominent Ci composers appeared such as Su Shi,Li Qingzhao,Xin Qiji and Lu You,etc.Song Ci remains popular even today.The book Three Hundred Song Ci Poems is very popular,and a good numbers of famous Ci poems have been set to new tunes for singing.
