.avo{
color: red;
background-color:grey;
width: 100%;
text-align:center;
}
.wm{
width:320px;
height:240px;
background-repeat: no-repeat;
background-size:contain;
background-position:center;
background-image: url("images/The_Earth_seen_from_Apollo_17.jpg");
}
.wm2{
width:320px;
height:240px;
background-repeat: no-repeat;
background-size:contain;
background-position:center;
background-image: url("https://upload.wikimedia.org/wikipedia/commons/9/97/The_Earth_seen_from_Apollo_17.jpg")
}