拖动到目标位置的元素还能拖动怎么解决

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>questionnaire</title>
<link rel="stylesheet" href="css/style.css">
<script src="https://cdn.bootcss.com/jquery/1.7/jquery.min.js"></script>
</head>
<body>
<section class="questionnaire">
<div class="left"><p>问卷</p></div>
<div class="right">
<div class="item" draggable="true">
<label for="name">姓名：</label>
<input type="text" id="name">
</div>
<div class="item" draggable="true">
<label for="old">年龄：</label>
<input type="text" id="old">
</div>
<div class="item" draggable="true">
<input type="radio" name="sex" value="male" id="male">
<label for="male">男</label>
<input type="radio" name="sex" value="female" id="female">
<label for="female">女</label>
</div>
<div class="item" draggable="true">
<input type="submit" value="提 交">
</div>
</div>
</section>
<script src="js/js.js"></script>
</body>
</html>

*{
    padding:0;
    margin:0;
}
.questionnaire{
    display: flex;
    margin-top: 20px;
}
.left{
    flex:1;
    text-align: center;
    border:1px solid #ccc;
    margin-left: 10px;
}
 
.left>.item{
    margin:0 auto 5px auto;
    padding:10px;
    max-width: 300px;
}
.left>.item>input{
    padding:5px;
}
.left>.item>input[type="submit"]{
    justify-content: center;
    text-align: center;
    width:180px;
    margin-left: 50px;
}
.left>.item>label[for="male"]{
    margin-right: 10px;
}
 
.right{
    flex:1;
}
.right>.item{
    margin-left: 100px;
    padding:10px;
    max-width: 300px;
    border:2px #999 dashed;
    margin-bottom: 10px;
}
.right>.item>input{
    padding:5px;
}
.right>.item>input[type="submit"]{
    justify-content: center;
    text-align: center;
    width:180px;
    margin-left: 50px;
}
.right>.item>label[for="male"]{
    margin-right: 10px;
}

var right=document.getElementsByClassName('right')[0],
    items=right.getElementsByClassName('item'),
    paper=document.getElementsByClassName('left')[0],
    dragItem=null;
right.addEventListener('dragstart',function(e){
    dragItem=e.target;
})
paper.ondragover=function(e){
    e.preventDefault();
}
paper.ondrop=function(e){
    // e.preventDefault();
    var newItem=dragItem.cloneNode(true);
    this.appendChild(newItem);
}