填空题 It is requested that every student writes a paper on sustainable development.
【正确答案】
【答案解析】writes应改为write或should write。[解析] 句中谓语动词是request的被动语态形式，因此其主语从句需用虚拟式动词，即谓语动词用原形或者should+动词原形。句意：每位学生被要求写一篇有关可持续发展的论文。