我在尝试创建一个崩溃组时遇到了一些问题。我有以下html：
<div class="panel-group row" id="accordion">
<div class="panel panel-default col-xs-3" id="panel1">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" data-parent="#accordion" href="#collapseOne">
Collapsible Group Item #1
</a>
</h4>
</div>
</div>
<div class="panel panel-default col-xs-3" id="panel2">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" data-parent="#accordion" href="#collapseTwo">
Collapsible Group Item #2
</a>
</h4>
</div>
</div>
<div class="panel panel-default col-xs-3" id="panel3">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" data-parent="#accordion" href="#collapseThree">
Collapsible Group Item #3
</a>
</h4>
</div>
</div>
</div>
<div class="row panel">
<div id="collapseOne" class="panel-collapse collapsed in">
<div class="panel-body">
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
</div>
</div>
<div id="collapseTwo" class="panel-collapse collapsed in">
<div class="panel-body">
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
</div>
</div>
<div id="collapseThree" class="panel-collapse collapsed in">
<div class="panel-body">
Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
</div>
</div>
</div>
其中的行为与this相同。我期待的是，崩溃始终显示在一行中。目前，当我打开其他崩溃时，我失去了关闭其他崩溃的能力。我做错了什么？
更新：
更确切地说，我希望行在当时只显示一次崩溃。此刻，这是不可能的。为什么呢？