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);
}