题目

NaHCO3俗名小苏打，下面是对小苏打采用不同分类法的分类，不正确的是    A．NaHCO3是碱                     B．NaHCO3是盐    C．NaHCO3是钠盐                   D．NaHCO3是碳酸盐 答案：A17．Although he was laughed at by his classmates，he insisted on attending the speech contest．（用过去分词作状语改写句子）Laughed/Although laughed at by his classmates，he insisted on attending the speech contest．．