如何使特定选项出现在select菜单中？

<select>
  <option value="option1">选项1</option>
  <option value="option2">选项2</option>
  <option value="option3">选项3</option>
</select>

<select id="mySelect"></select>

<script>
  var select = document.getElementById("mySelect");
  
  var option1 = document.createElement("option");
  option1.text = "选项1";
  option1.value = "option1";
  select.appendChild(option1);
  
  var option2 = document.createElement("option");
  option2.text = "选项2";
  option2.value = "option2";
  select.appendChild(option2);
  
  var option3 = document.createElement("option");
  option3.text = "选项3";
  option3.value = "option3";
  select.appendChild(option3);
</script>