#resImage_250 {
    display:block;
    overflow:hidden;
    background-image:url('https://www.articulategroup.co.uk/assets/images/6/fire-sq-7e15c30a.jpg');
    background-repeat:no-repeat;
    background-position:center center;
        width:100%;
    background-size: cover;
        height:420px;
}
@media screen and (min-width:700px){
    #resImage_250 {
        background-image:url('https://www.articulategroup.co.uk/assets/images/0/fire-6d8790d2.jpg');
                height:500px;
    }
}
@media screen and (min-width:1000px){
    #resImage_250 {
        background-image:url('https://www.articulategroup.co.uk/assets/images/1/fire-2753a8ea.jpg');
                height:620px;
    }
}
@media screen and (min-width:1400px){
    #resImage_250 {
        background-image:url('https://www.articulategroup.co.uk/assets/images/e/fire-7a63e0dc.jpg');
                height:620px;
    }
}