What are the three modes of vim, and how do you switch between the three modes?

Why should you always exit vim via esc:x before closing your Terminal window?

If you lose your network connection while editing a file in vim, what do you need to do before starting vim again?

What is the purpose of the first line in a python or shell scripting file?

What command must you run to make a script executable, and when do you need to run it?

Assume the script hello_world.sh is in the $PATH environment variable, but the script try_this.sh is not. try_this.sh is in your working directory. Give the specific command to execute each of these scripts.