Question #4

<div class="block1">
  <div class="block2">
    <div class="block3">
      <div class="block4">
        <div class="block5">
          text
        </div>
      </div>
    </div>
  </div>
</div>

div div .block3 .block4 {
  color: green;
}

.block1 .block3 div div {
  color: red;
}

div .block4 .block5 {
  color: blue;
}