we can do it easily like below
maybe it will work for a novice like me :)
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Sample</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css" />
</head>
<body>
<div class="container-fluid">
<div class="col-md-8">
<div class="row">
<div class="col-sm">
<label for="AA">A</label>
<input type="text" name="AA" />
</div>
<div class="col-sm">
<label for="BB">B</label>
<input type="text" name="BB" />
</div>
</div>
<div class="row mt-5">
<div class="col-sm">
<label for="CC">C</label>
<input type="text" name="CC" />
</div>
<div class="col-sm">
<label for="DD">D</label>
<input type="text" name="DD" />
</div>
</div>
</div>
<div class="mt-5">
<div class="col-md-8">
<div class="row">
<div class="col-sm">
<label for="AAA">A</label>
<input type="text" name="AAA" />
</div>
<div class="col-sm">
<label for="CCC">C</label>
<input type="text" name="CCC" />
</div>
</div>
<div class="row mt-5">
<div class="col-sm">
<label for="BBB">B</label>
<input type="text" name="BBB" />
</div>
<div class="col-sm">
<label for="DDD">D</label>
<input type="text" name="DDD" />
</div>
</div>
</div>
</div>
</div>
</body>
</html>
Demo
