This is a collective noun. Though it appears in the singular form, it takes a plural predicate verb. 它是一个集合名词。虽然形式上是单数,它必须跟复数的谓语动词。
Proper names and definite descriptions are singular conceptions in traditional logic, while they are named as singular terms in predicate logic. 传统逻辑中专名和限定摹状词都是单独概念,在谓词逻辑中则被称为个体词。