<!DOCTYPE html>
<!--
 | The value "pre-line" of property "white-space" allows wrapping and collapses
 | white-space.
 |   https://www.w3.org/TR/css3-text/#white-space-property
 -->
<html>
<head>
  <style>
    body {
      margin: 0px;
      font-family: Roboto;
      font-size: 20px;
    }
    .containing-block {
      background-color: #03a9f4;
      width: 200px;
    }
    .pre-line-class {
      white-space: pre-line;
    }
  </style>
</head>
<body>
  <div class="containing-block">
    <span class="pre-line-class">abc  def  ghi  jkl  mno  pqr  stu  vwx  yz</span>
  </div>
</body>
</html>