五星战队大神龙视频:wml程序初学者问个问题

<card id="hobbiescard" title="Hobbies">
<p>
What''s your hobbies?
<select name="hobbies" multiple="true">
<optgroup title="Computer">
<option value="Software">Software</option>
<option value="Hardware">Hardware</option>
</optgroup>
<optgroup title="Sports">
<option value="Swimming">Swimming</option>
<option value="Skiiing">Skiiing</option>
<option value="Bicycle">Bicycle</option>
<option value="Tennis">Tennis</option>
</optgroup>
<optgroup title="Book">
<option value="Literature">Literature</option>
<option value="Technology">Technology</option>
</optgroup>
<optgroup title="Entertainment">
<option value="Films">Films</option>
<option value="TV">TV</option>
<option value="Dancing">Dancing</option>
<option value="Bar">Bar</option>
</optgroup>
</select>
</p>
</card>

效果：

------ Hobbies -----
What''s your hobbies?
1 Computer
2>Sports
3 Book
4 Entertainment

OK

效果有错吗？“2>Sports”是不是指默认选第二项？是不是分组下面有多个项目才要 “multiple="true”设置？
老手帮我回答一下吧!