Hearing loss in a large number of teenagers caused because of their listening to loud musi

问题补充：

Hearing loss in a large number of teenagers caused because of their listening to loud music.

A. is

B. has

C. are

D. have

答案：

(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。