I will never forget somgthing.I had an exciting experience last Sunday.I took the bus to go home ,it was very crowded,it was full of people.Everyone was trying to move so that could get off.But a man was always standing in the middle.I thought he was strange.Suddenly,he put his hand into a woman's bag,and I noticed that he was a thief !Then I told the woman about it .The woman was surprised and called the police.At last the thief was caught ,and I thought I did a good thing ,I was so happy.Helping others is great!
（不知道标志词用过去式可以不）