Word Network: 開く

to open (a door, window, etc.)

The act of opening up a closed space, facility, or system to make it accessible to others. It is commonly used for leaving doors/windows open or opening private facilities like parks or schools to the general public.

to close (intransitive)

To close (transitive, e.g., book).

The act of starting or beginning a process, event, or action. It is a formal noun often used in professional or official contexts to signify the commencement of something scheduled.