【题目】His parents won't allow him to go to study in the USA alone.
His parents won't him to study in the USA alone.

【答案】approve；of；going
【解析】句意：她的父母不允许他一个人在美国学习。approve of doing sth.固定短语，“赞成做某事”，根据所给内容，可知答案为approve ； of ；going。