.newbanner_2020{ margin:20px auto; width:1000px;}
.newbanner_2020 div{ width:490px;float:left; margin-bottom:12px;}
.newbanner_2020 div img{ width:490px; height:90px;}
.newbanner_2020 div:nth-child(1){ float:left;}
.newbanner_2020 div:nth-child(2){ float:right}
.newbanner_2020 div:nth-child(3){ float:left;}
.newbanner_2020 div:nth-child(4){ float:right}