根据短文内容，将所给的词的恰当形式填入填在横线上。

    This summer holiday I'll (write) a story! It will (be) a fantasy (魔幻) story like the Harry Potter books. I'll write about 10,000 words. The characters (人物) in my story (be) four lovely girls. They (live) ordinary (普通的) lives. But one day something (change) their lives forever. It'll be a wonderful book.