Highlighting citations along with some long sentences starting in the middle of paragraphs

I am trying to highlight my revised paper in latex, since when I highlight its PDF using Foxit the highlights are not shown after pressing generate PDF in journal’s website.

I have some troubles: I must sometimes highlight citations, so I tried hl{cite{c1}} by usepackage{xcolor}.

Some lines later, I need to highlight some paragraphs. when I tryied hl{long text}, all the text was written in one line! So I decided to highlight it using begin{highlight}some long text end{highlight}

In the next part of the paper, I need just to highlight a sentence starting in the middle of a line up to in the middle of some lines next! I have tried using the soul package, but it wasn’t possible beside xcolor package.

What should I do? I have these features in my paper: some citations to be highlighted, some long paragraphs to be highlighted, some sentences starting in the middle of a line (some lines long), and some figures (I know I should use framebox for figures, but I just mentioned it to be sure not any further package for solving previously mentioned parts makes problem with this simultaniously).

(Beside the problems, I even didn’t see the shape of begin{highlight}...end{highlight} appropriate. Because it adds indentations to the paragraphs and changes the appearance of the paragraph)