Please solve the Linux command. I don't need an explanation I just need only command solution

13. Write a one-line expression that write to the file number_of_users.txt the number of users with a UID between 1000 and 10000. 14. Use command wget to download 2 files from urls: url1 url2, which word has been removed from the file downloaded with url2? 15. Create a directory which name is its creation date and time (with accuracy to seconds) in ISO8601 format 16. What does the system call wait() do when run with parameter-1