Most of the old customs here have ________ already．

A.died down

B.died off

C.died out

D.dies away

答案及解析： C

解析：

die out(习俗、做法等)消失、过时；die down(火焰、风暴等)逐渐减弱；die away(声音等)减弱；die off先后死去。