Hearing loss in a large number of teenagers caused because of their listening to loud music.
A. is
B. has
C. are
D. have
网友回答
(答案→)A. is
B. has
C. are
D. have
解析：句意：大多数年轻人听力的损伤是因为他们听了特别大的音乐而引起的。Hearing loss in a large number of teenagers是动名词短语做主语，当动名词短语做主语时谓语动词用单数，这里句子的主语与cause之间是被动关系，故选A。