Firstly,it delimits the object of the study,distinguishes between numeral adjective interrogatory pronoun and numeral phrase and concludes that numeral is a type of closed word class.

• 首先，在理论上明确了研究对象，对数词与助词、形容词、疑问代词、数词词组作了区别，得出了数词是一个封闭的词类的结论。