Today is the last Saturday before Christmas. Everyone in the USA 1 shopping for presents. 2 is falling. People are walking fast. They are trying to keep3 when they move from shop to shop. In the shops children are 4 at the toys. They are talking to a man called Father Christmas. He asks, "What do you want for Christmas?"

    In the USA it is warm and beautiful in summer. The trees and fields are green then. But now it is winter and 5is white.

    At 6, small lights make the houses and buildings 7. Christmas is a beautiful 8 of a year.

    Christmas Day always begins before 9. Children wake up very early in the morning. They open the 10from their parents. Then they wake up their parents, saying "Merry Christmas."

阅读材料：

材料：大江东去，浪淘尽，千古风流人物。故垒西边，人道是、三国周郎赤壁。乱石穿空，惊涛拍岸，卷起千堆雪。江山如画，一时多少豪杰。

遥想公谨当年，小乔初嫁了，雄姿英发。羽扇纶巾，谈笑间、强虏灰飞烟灭。故国神游，多情应笑我，早生华发。人间如梦，一尊还酹江月。

--摘自《念奴娇·赤壁怀古》

请回答：

向暖水瓶中灌开水时，有经验的人通过声音就知道水是否快满了．