A. The Undo button is used when a mistake is made and you want to change something back to how it was, every time the undo button is clicked a recent action that has been done, the action that is undone is everything you’ve typed without clicking away or stopped for a while.
B. The redo button is the opposite of the undo doing the same thing by recreating what you may have undid on accident. This button is at the very top next to the save button the, on its left is the undo button
C. Zoom tool is used when you cannot read something, so on the bottom left you either click the + to zoom in, - to zoom out. The percentage shows what percent you are zoomed in or out.
D. The number of pages tells you currently how many pages you have typed and what page you are currently looking at.
E. The ruler is used to determine where to put something exactly to turn it on press the little button circled below and it will turn on a ruler circled below.