Oops, try again. Add a <div class="thumbnail">..</div>


#1

<div class="row">
    <div class="col-md-4">
    <div class="thumbnail">
    <img src="http://goo.gl/0sX3jq">
    </div>
    
    <div class="thumbnail">
    <img src="http://goo.gl/an2HXY">
    </div>
    
    <div class="col-md-4">
    <div class="thumbnail">
    <img src="http://goo.gl/Av1pac">
    </div>
    </div>
    
    <div class="thumbnail">
    <img src="http://goo.gl/vw43v1">
    </div>
    
    <div class="col-md-4">
    <div class="thumbnail">
    <img src="http://goo.gl/0Kd7UO">
    </div>
    </div>

Please help what am I doing wrong? it is saying Oops, try again. Add a <div class="thumbnail">..</div>... what am i missing or forgetting to close


Oops, try again. Add a <div class="thumbnail">..</div> why?
#2

you forgot to close your col-md-4 before starting a new one:

<div class="col-md-4">
    <div class="thumbnail">
    <img src="http://goo.gl/0sX3jq">
    </div>
    
    <div class="thumbnail">
    <img src="http://goo.gl/an2HXY">
    </div>
   <!-- missing div closing tag to close the col -->    
    <div class="col-md-4">

Same for your second col, you also forgot to close it