For example, when you add a border, you add it after selecting All.

For example, if you want to draw a border in A 1:G 1, a border will be added after clicking the line 1.

Or, if you want to add a border in A 1:A20, you can add it to the selected column A. ..

And then there are some formulas,

For example, the input of C 1 is

=if(a 1= ""，" "，a 1*b 1)

You pull down the formula, but you don't pull it into your actual area. For example, there is only 100 line, but you pull it to C 1000 or even C 10000.

Then maybe some picture controls or something.

This thing is not easy to guess, mainly by experience.