题目解析:
C core: 核心,中心。A是材料,原料;B是层,层次;C是中心;D是框架,结构。所以C的center正确。 对应原文 By contrast, wooden statues were carved from several pieces of wood that were pegged together to form the finished work, and metal statues were either made by wrapping sheet metal around a wooden core or cast by the lost wax process. core所在的半句说金属塑像是把金属薄片包在木头的什么上做成的;既然外面包的是金属,说明木头是里面的内核,所以是中心的意思。A材料和B层都没有内外对应的意思,错;D的frame框架应该是在外面的,与意思不符。