我按照视频里讲的做出来成这个样子了。。。

左右两边是灰色的，我想做成纯白色的，还有我设置的高度是红线到顶，可是图片还是都显示出来了，请问这是什么情况。。。代码是从bootstrap上复制下来的，如下：

<div id="carousel-example-generic" class="carousel slide" data-ride="carousel">
  <!-- Indicators -->
  <ol class="carousel-indicators">
    <li data-target="#carousel-example-generic" data-slide-to="0" class="active"></li>
    <li data-target="#carousel-example-generic" data-slide-to="1"></li>
  </ol>

  <!-- Wrapper for slides -->
  <div class="carousel-inner" role="listbox">
    <div class="item active">
      <img src="mac.jpg" alt="mac">
      <div class="carousel-caption">
        
      </div>
    </div>
    <div class="item">
      <img src="chrome.jpg" alt="chrome">
      <div class="carousel-caption">
       
      </div>
    </div>
    
  </div>

  <!-- Controls -->
  <a class="left carousel-control" href="#carousel-example-generic" role="button" data-slide="prev">
    <span class="glyphicon glyphicon-chevron-left"></span>
    <span class="sr-only">Previous</span>
  </a>
  <a class="right carousel-control" href="#carousel-example-generic" role="button" data-slide="next">
    <span class="glyphicon glyphicon-chevron-right"></span>
    <span class="sr-only">Next</span>
  </a>
</div>