Music,for both of us,is a part of life we treasure,and Michael has found his records and tapes a constant ____________ o
问题描述：
Music,for both of us,is a part of life we treasure,and Michael has found his records and tapes a constant ____________ of happiness during the long hours of inactivity forced upon him.
A.source B.illustration C.addition D.package
请选择,并讲讲理由.
答
A
a constant source of happiness 欢乐的不竭源泉