It was a nice day last Sunday.Susan took her sister to the aquarium。

when they arrived ，they find there were hundred and thousand people。

after a while，they decided to see the sharks in the pool。

Susan was watching the sharks carefully，when the perform over,she found her sister disappeared。

she was very worrying about her sister,so susan got to the staff,told him about what happened,the staff helped her find her sister finally，her sister was playing with another girl。

she said thanks to the staff，told her sister never leave her again。

呵呵，有什么疑问欢迎讨论，希望采纳哦。