How time flies!This is a third year that I have been in this school．In the past two years，our school had organized many activities．That impressed me most was an activity calling"Learning to Farm"．In an autumn afternoon，we went to a farm which we learned to plant potatoes．Having been in the city for so a long time，we were so happy to go to the countryside．After we were divided into 3groups，we started to work．Some students cut potatoes into pieces； some dug holes，and the others put the pieces into the hole，put the earth back and pushed them down hard．We continued doing that until all the work was done．Although we were exhausted，but we felt happy on our way home．

　　详

　　1．a改为the，考查冠词，形容词最高级前应用定冠词the．

　　2．had改为has；考查动词的时态，inthepasttwoandahalfyears应与现在完成时连用．

　　3．That改为What；考查名词性从句，这是一个主语从句，疑问代词what在从句中作主语．

　　4．calling改为called；考查分词作定语，activity与动词call存在逻辑上的动宾关系，故用过去分词形式作后置定语．

　　5．In改为on；考查介词，在具体到某一天的下午时，应使用介词on．

　　6．which改为where或者前面加on考查定语从句，关系词指代先行词farm，在从句中作状语所以用where或onwhich．

　　7．so改为such；考查固定结构，so+形容词+a+名词，such+a+形容词+名词．

　　8．hole改为holes；考查名词单复数，根据上文的somedugholes，可知此处要用复数形式holes．

　　9．them改为it，考查代词，it在这里代替上文的不可数名词theearth．

　　10．去掉but，考查连词，在英语中although可与yet，still连用，但不与but连用，although用在句首，所以去掉but．