SOURCE

 function change(){
     // 获取select选中的值
    let selectValue = document.getElementById('select').value
    console.log(selectValue)
    // 如果是volvo则隐藏id = vovo的div
    if(selectValue === 'volvo') {
        console.log(selectValue)
        document.getElementById('vovo').style.display = 'none'
    }
}

<select id="select" onchange="change()">
  <option value ="volvo">Volvo</option>
  <option value ="saab">Saab</option>
  <option value="opel">Opel</option>
  <option value="audi">Audi</option>
</select>
<div id="vovo" class="vovo">
    vovo不显示
</div>
<div class="audi">
    vovo显示
</div>