body {
  margin: 0;
}

div {
  width: 100%;
  height: 100vh;
  text-align: center;
  background-size: cover;
  background-position: 50% 50%;
  color:#fff;

}
h1,h2 { position:relative; top:50%;}
.one {
  background-image: url('https://unsplash.it/1920/1200?image=810');
}

.two {
  background-image: url('https://unsplash.it/1920/1200?image=797');
}

.three {
  background-image: url('https://unsplash.it/1920/1200?image=792');
}