JSFiddle - React, Tailwind, and code Playground

HTML

<select class="selectElement"> 
  <option>a</option>
  <option>b</option> 
</select>
<select class="selectElement"> 
  <option>c</option>
  <option>d</option> 
</select>
<select class="selectElement"> 
  <option>e</option>
  <option>f</option> 
</select>
<a onclick="alert('a')">asd</a>

JavaScript

document.addEventListener("click",handler,true);

function handler(e){
    e.stopPropagation();
    e.preventDefault();
}

function cancelDropDown(ev) {
  ev.preventDefault();
}

var showMenu = document.getElementsByClassName("selectElement");

// ...

for ( var i = 0; i < showMenu.length; ++i ) {
    showMenu[i].addEventListener("mousedown", cancelDropDown, false);
}