是on还是at So we should put away our mobiles phone and focus ou

是on还是at So we should put away our mobiles phone and focus ou ( ),I have to put it away and focus my attention on study th ____.I have to put it away and focus my attention on study t [ ],i have to put it away and focus[集中] my attention on stud ,I have to put it away and focus my attention on study this We will put your story and photo on our Friendship Page so _ 是be focus on 还是focus on we went to the train station and saw our friend（ ） A.on B.ou we must put our things away both before class and after clas 英语翻译On what information should we focus?Concept:Theeconomic 是focus on还是be focused on After we arrived at the mountain ,we () our tents A.put on B