因为use可以做名词
noun
[mass noun]
the action of using something or the state of being used for some purpose
用,使用
a member of staff is present when the pool is in use.
游泳池开放时,有一工作人员在场.
theatre owners were charging too much for the use of their venues.
剧院老板对场地使用要价太高.
■the ability or power to exercise or manipulate something,especially one's mind or body
（尤指思想,体力）运用能力,使用
the horse lost the use of his hind legs.
这马丧失了后腿活动能力.