"Book sale" 或 "book fair" 是指图书售卖活动。
来源："Sale" 是指出售商品或服务，"book" 是指书籍。"Fair" 指的是展览会，聚集了很多的书商或者书商和书迷一起参观展销会。
例句：
There's a book sale happening at the pbrary next week.
(下周图书馆有一场图书售卖活动)
I always find great deals at the book fair.
(我总是在书展上找到很多优惠)
I'm planning to go to the annual book sale at the bookstore.
(我打算去书店的年度图书售卖活动)