代码：
DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>title>
<style type="text/css">
*{
padding: 0;
margin: 0;;
}
#contenier{
display: flex;
flex-direction: column;
justify-content: stretch;
align-items: center;
height: 1000px;
}
.box1{
display: flex;
flex-direction: row;
flex-grow: 1;
justify-content: space-around;
align-items: center;
width: 100%;
}
.box2{
border-radius: 200%;
width: 30%;
height: 80%;
background-color: red;
border: 1px solid #000000;
}
style>
head>
<body>
<div id="contenier">
<div class="box1">
<div class="box2">div>
<div class="box2">div>
div>
<div class="box1">
<div class="box2">div>
div>
<div class="box1">
<div class="box2">div>
<div class="box2">div>
div>
div>
body>
html>
效果图：