What is the command for creating directories?

How to list all active jobs in the terminal?

Which option is used to check if a string is not null?

Which command compares two sorted files line by line? 

What is cron?

What command is used to print the current working directory?

Which command is used to change the file extension of a file?

The syntax for using && is ______________

Which command is used by the superuser to change the root password?

When we log in, the UNIX system places us in a directory, called the _____ directory.