Book as a noun in the sentence means book, book; Works, printed (or electronic) publications; A book, a book; A book (set); Account books, accounts and accounting books; Articles, volumes and parts of long works; Roster (of customers or employees); Bet records. As a verb, it means, make an appointment, make an appointment; Put ... on record (by the police); Registered warning (for players who break the rules). On its various forms, plural: books; ; Third person singular: books; ; The present continuous tense: booking；; Past tense: booked；; Past participle: booked. She is looking for a theme for her new book. She is going to write a new book and is looking for a theme.

Sales is used as a noun in the sentence, which means to sell; Sales; Sales volume; Sales department. When used as an adjective, it means to sell; About sales. Take the sentence of sales as an example. The sales manager will introduce new products. The marketing manager will hold a new product promotion meeting.

As a noun, activities in the sentence means lively situation; Active; Activity (for interest, entertainment or a certain purpose), the plural of activity. There are various children's activities. It means, "There are all kinds of activities suitable for children."