The old man's clothes, () old and worn, looked clean and of good

The old man's clothes, () old and worn, looked clean and of good quality.
A、if
B、when
C、though
D、since
【正确答案】：C
【题目解析】：句意：这位老人的衣服虽然又旧又破，但看上去干净整洁，质量很好。f意为"如果”，when意为当时候”，though意为"虽然”，since意为"因为”，故选C。此处是though引导的让步状语从句的省略现象，当though引导的从句中的主语与主句主语相同，且从句的谓语又是he动词时，那么从句中的主语和 be动词可以省略，补充完整为"though they were old and worn"。