Complete the paragraph:
I was walking happily in my favourite park, enjoying the weather, but suddenly......
It seems as if this assignment is designed to make you use your imagination — not to use our imagination. It is very much like the Rorschach ink blots in psychology, which present vague stimuli to elicit a response. It is an "ink blot" using words.
Ask yourself, what might suddenly happen in the park? How would I respond to that event? How would the event turn out? That is your paragraph.
I hope this helps. Thanks for asking.