根据语境从方框中选择恰当的短语填空。有的需要变换形式。每个短语限用一次。

knock, come, look, colour, ready, cut, open, symbol activity, also

    Halloween is all important holiday in America. It ____on the evening of every 31st October. The pumpkin(南瓜)is a(n) ____of Halloween. So orange has become one of the traditional Halloween ____. Another traditional colour is black. It is probably because Halloween ____take place(发生)at night. Every autumn, when vegetables are ____, children pick large orange pumpkins. Then they ____faces in pumpkins and put burning candles (蜡烛) in them. It looks as if there was a person ____out of the pumpkin. Children ____like wearing strange masks(面具)and clothes every Halloween. They carry bags and ____on neighbours'doors from house to house. The neighbours ____their doors and put sweets or fruit in their bags. If people don't give them food, the children will play a trick (恶作剧)on them.