以下标有题号的每一行均有一个错误，请找出，并改正。
My parents and I went to the zoo on last Sunday.     1.              
There were a lot of visitors stood in front of the   2._______________
ticket window. We waited for a long time and buy three      3.              
tickets in the Monkey Mountain World of the zoo. I was     4.              
too eager to see the smart and funny animals, but I     5.              
quickened my steps through the crowd. Unfortunate,    6.              
I got separated from my parents. I had hard time looking     7.              
for him. But no luck. Wandering in the zoo, I felt    8.              
alone without companions. Worse still, I had no money,      9.              
so I had to walk home, covered as much as 10 miles.    10.