<!DOCTYPE html>
<html>
<body>
<p>单击该按钮可显示数字的自然对数。</p>
<button onclick="myFunction()">试一试</button>
<p id="demo"></p>
<script>
function myFunction() {
document.getElementById("demo").innerHTML = Math.log(2);
}
</script>
</body>
</html>