考研英语高频词汇opening n.孔,洞;职位空缺,工作机会ad开始的,开幕的<历年真题考查频次:23次>真题复现1:But it has already sparked significant controversy, with the Unite Sates trade representative opening an investigation into whether the tax discriminates against American companies, which in turn could lead to trade sanctions against France(2020年英语一 text4P2)