br标签不加/有什么后果，换行都必须使用<br />?
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>form中的lable标签</title>
</head>
<body>
<form>
<label>选择性别开启运动旅程：
<br /> <br />
<label for="male">男</label>
<input type="radio" name="gender" id="male" />
<br>
<label for="female">女</label>
<input type="radio" name="gender" id="female" />
<br /><br />
<label>你对什么运动感兴趣：</label>
<br /><br />
<label for="jogging">慢跑</label>
<input type="checkbox" name="Sport" id="jogging"/>
<br>
<label for="Mountain climbing">登山</label>
<input type="checkbox" name="Sport" id="Mountain climbing"/>
<br>
<label for="basketball">篮球</label>
<input type="checkbox" name="Sport" id="Mountain climbing"/>
<br /> <br />
<label for="email">输入你的邮箱地址</label>
<input type="email" id="email" placeholder="Enter email">
</form>
</body>
</html>
