How to remove table dividing lines in web pages_HTML/Xhtml_Web page production

How to remove the dividing line from the web page table.

In fact, the three tables above have three rows and three columns. The trick to hiding the separators lies in rules. Looking at the source code of these three tables, we can see that there are rules in the tag. . It has three parameters (cols, rows, none). When rules=cols, the table will hide the vertical separators, so that we can only see the rows of the table; when rules=rows, the horizontal separators will be hidden. , so that we can only see the columns of the table; when rules=none, both the vertical and horizontal separators will be hidden.