JSFiddle - React, Tailwind, and code Playground

HTML

<div id="a1">раз</div>
<div id="a2">два</div>
<div id="a3">три</div>

JavaScript

a3.onmousedown  = function() {
    //document.getElementById('a1').style.display='none';
    //document.getElementById('a2').style.display='none';
    document.getElementById('a1', 'a2').style.display='none';
}