body{
  margin:0;
  padding:0;
}
.container{
  position:relative;
  width:100%;
}
.container .section{
  position:sticky;
  top:0;
  width:100%;
  height:100vh;
  background:#000;
}
.container .section:nth-child(1){
  background: url(https://subjects.netlify.app/biology/res/anatomy%20app.png);
  background-size:cover;
}
.container .section:nth-child(2){
  background: url(https://subjects.netlify.app/biology/res/human%20body%20rendering.png);
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}
.container .section:nth-child(3){
  background: url(https://subjects.netlify.app/biology/res/human%20proportions%20game.png);
  background-size:cover;
}
.container .section:nth-child(4){
  background: url(https://subjects.netlify.app/biology/res/Use%20Selecting%20a%20Region%20in%20Human%20Body.png);
  background-size:cover;
}
.container .section:nth-child(5){
  background: url(https://subjects.netlify.app/biology/res/skinned%20human.png);
  background-size:cover;
}
.container .section:nth-child(6){
  background: url(https://subjects.netlify.app/biology/res/beating%20heart.png);
  background-size:cover;
}