英语作文no more mystery in bell tower neighborhood

We now know what was happening on Bell Tower neighborhood.The director of the local zoo says that three monkeys escaped from the cage.
These monkeys used to be researched in experiments by scientists in a animal lab the the capital city,one of the experiments is call "knocking-bell",in the experiments the monkeys were trained to knock bells for bananas.
These monkeys were give to the zoo as gift last year,after the they had escaped into the bell tower,they all tried their best to knok the bell for food at meal time.That is the mystery in bell tower neighborhood,and now,there is no more.