请问下面的英文句子有语法错误吗?如果有帮忙改正下,
问题描述：
请问下面的英文句子有语法错误吗?如果有帮忙改正下,
Xanthan gum (XG),discovered by the Northern Regional Research Laboratories (NRRL) of the United States Department of Agriculture,is a complex non-linear anionic microbial exo-polysaccharide.
答
没有语法错误.句子结构：主系表主语：Xanthan gum系动词：is表语：a complex ...exo-polysaccharide过去分词短语 discovered by ...作定语,修饰Xanthan gum,不需要was.如果改为定语从句,则需要was,即：Xanthan gum,w...