html代码：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>Page Title</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" type="text/css" media="screen" href="style.css" />
</head>
<body>
<audio id="sounds" loop= "false" volume = "60">
<source src="sounds/clap.wav" id="A" type="audio/wav">
<source src="sounds/boom.wav" id="S" type="audio/wav">
<source src="sounds/hihat.wav" id="D" type="audio/wav">
<source src="sounds/kick.wav" id="F" type="audio/wav">
<source src="sounds/snare.wav" id="G" type="audio/wav">
<source src="sounds/ride.wav" id="H" type="audio/wav">
<source src="sounds/tom.wav" id="J" type="audio/wav">
</audio>
<div class="keys">
<div class="key">
<button id="common1" class="key_link" type="submit">CLAP</button>
</div>
<div class="key">
<a href="#" id="common2" type="button" class="key_link">BOOM</a>
</div>
<div class="key"> …javascript ×1