Question

press the_key to turn on and off the extend function​

Answer 1

Press the Esc key to turn on and off the extend function​.

Answer 2

Answer:

Esc Key

When you move the cursor using the cursor control keys, the size of the text selection changes and the letters EXT appear on the status bar. You turn off the extend mode by pressing the Esc key. One of the handy things to do in extend mode is to search for other text