console 命令行工具 X clear

console

function removeOption()
  {
  var x=document.getElementById("mySelect")
  x.remove(x.selectedIndex)
  }

<form> 
  <select id="mySelect"> <option>苹果</option> <option>桃子</option> <option>香蕉</option> <option>桔子</option> </select> 
  <input type="button" onclick="removeOption()" value="删除被选的选项"> 
 </form>