I can't go out because it's snowing heavily.          

很多学者认为，公元1500年前后是人类历史的一个重要的分水岭，从那个时候开始，人类的历史才称得上是真正意义上的世界历史，这里“分水岭”的含义是（  ）

    I think Christmas (圣诞节) is one of the happiest times of the year. Everyone has a smile on their face. It's such a(n) ____for kids. They can't wait to open their gifts and play with their____. It's a nice time for their parents too. They can ____with their family and relax. Let's not forget the true meaning of Christmas.  It is not about ____ Christmas trees or the snowman. It's all about love for each other and ____around the world.

这20户家庭日用电量的众数、中位数分别是（　　）