One year,two boys decided to play a trick___41___April Fool'

One year,two boys decided to play a trick___41___April Fool's Day．求解一篇完型
One year,two boys decided to play a trick___41___April Fool's Day．They
went into the ___42___at lunchtime；there were a lot of people there．Suddenly they
started to shout at each other and then started___43___．They had a terrible fight and
one became very angry with the other．While they were 6ghting．one fell to the
ground and the other kicked___44___,then hurried off．Some people in the park ran
to___45___the boy on the ground．He shouted loudly,"Oh,my arm!Oh,my leg!"
A kind woman took out her___46___and started to call the hospital．At that
moment,the boy got to his feet,cried"April Fool!"and started to run away．It
happened SO suddenly that everyone around was___47___．Two park keepers nearby
also saw'the fight．They ran quickly___48___caught the two boys．"You___49___
fight in the park,"they said．The two boys smiled and said,April Fools!''
The park keepers laughed and let them___50___．
41．A．in B．on C．at D．to
42．A．school B．hall C．ZOO D．park
43．A．fighting B．running C．jumping D．smiling
44．A．me B．you C．him D．her
45．A．train B．help C．knock D．bite
46．A．camera B．walkman C．mobile phone D．Wallet
47．A．happy B．sad C．excited D．surprised
48．A．and B．but C．SO D．or
49．A．can B．may C．mustn't D．don't
50．A．go B．to go C．going D．went