There are a few ways to add lines in Excel. The easiest way is to use the "drawing tools" option. First, select the cells that you want to include in the line. Next, click on the "drawing tools" tab at the top of the screen. Then, select the "line" option and draw the line between the cells.

Another way to add lines is to use the "border" option. First, select the cells that you want to include in the line. Next, click on the "border" tab at the top of the screen. Then, select the "line" option and draw the line between the cells.

Finally, you can also add lines by using the "format cells" option. First, select the cells that you want to include in the line. Next, click on the "format cells" tab at the top of the screen. Then, select the "border" option and draw the line between the cells.