问引导转盘滑块正在工作，但图像不显示

EN

.about #plas-slider {
  margin-top: 40px;
  height: 611px;
  width: 1360px;
  float: right;
}

.about #plas-slider a {
  position: absolute;
  width: 64px;
  height: 64px;
  float: left;
}

.about #plas-slider .carousel-control-prev {
  left: 0;
}

.about #plas-slider .carousel-control-next {
  left: 64px;
}

.about #plas-slider a img {
  height: 64px;
  width: 64px;
  float: left;
}

<section class="about">
  <div id="plas-slider" class="carousel slide" data-ride="carousel" data-interval="false">
    <div class="carousel-inner">
      <div class="carousel-item active">
        <img src="/Assets/images/s3x-2691-1033-1135.png" class="d-block w-100 img-fluid" alt="Slide 1">
      </div>
      <div class="carousel-item">
        <img src="/Assets/images/s3x-2691-1033-1136.png" class="d-block w-100 img-fluid" alt="Slide 2">
      </div>
      <div class="controls">
        <a class="carousel-control-prev" href="#plas-slider" role="button" data-slide="prev">
          <img class="img-fluid" src="Assets/images/Group 381.png" aria-hidden="true" />
          <span class="sr-only">Previous</span>
        </a>
        <a class="carousel-control-next" href="#plas-slider" role="button" data-slide="next">
          <img class="img-fluid" src="Assets/images/Group 380.png" aria-hidden="true" />
          <span class="sr-only">Next</span>
        </a>
      </div>
    </div>
  </div>
</section>