Answer and Explanation
Mariel types a sentence. She then decides to include that sentence four more times
He/she used CTRL+C which is a computer command which is used to copy a highlighted text to a clipboard. It is generated by pressing the C key while holding down the Ctrl key on most computer keyboard. To include it for more times he/she has to use a command to paste which is CTRL+V this command helps to paste the contents of the clipboard into the current cursor location.
She then decides she only wants the sentence three more times, but changes her mind again to include the last sentence.Here she will use the CTRL+Z which is a command used to redo and CTRL+Y.