In the past few years, My Heart Will Go On was a popular song among
young people, were often heard singing it at parties
A. they
Bthat
Cwho
D. which
网友回答
A. they
B. that
(答案→)C. who
D. which
解析：考查非限制性定语从句：句意：在过去几年，我心依旧这首歌在年轻人中很受欢迎，经常在聚会上听到他们在唱这首歌。因为定语从句是人被听见唱歌，所以缺少的主语是人，用who引导限制性定语从句，that不能做限制性定语从句。选C。