Sentence:  Anyone who has worked with Littlewood will wince at the memory of going over single <WSD>lines</WSD> time and time again, each actor in turn speaking the <WSD>line</WSD> until the valid intonation, phasing and emphasis emerged. 
Meaning of the word marked with <WSD> tags:  A sentence of dialogue, especially (from the later 19thc.) in a play, movie(,) or the like.