【答案】 are ; used ; were developed ; earliest ; an ; that / which ; maintaining ; pronunciation;frequently;of 【解析】【分析】本文是一篇说明文,讲述了筷子在我国的历史、作用和文化意义。 (1)考查时态。分析句子结构可知,此处是句子谓语动词,根据下文的 is 判断为一般现 在时,主语 chops...