line height disappears when it loads content

[ikhsank6]

I have html content like the following.
<p data-indent="2" data-line-height="1">Example1</p><p data-indent="2" data-line-height="1">Example2</p>
when i open the editor, the data-line-height disappears from the html content that i have set.

is there any alternative to add lien height between sentences?