The story is sad. It is happening in the twenty first century.

这是个悲伤的故事。这件事发生在21世纪。

Twenty first graders and six educators were killed in the December 2012 school shooting in Newtown.

2012年12月纽敦市发生的校园枪击案造成20名一年级学生和6名教育工作者遇害。

In the UK, the most important birthday is the twenty first, and many Brits throw huge parties for that event.

在英国，二十一岁的生日最重要，许多英国人为此安排盛大的聚会。

We're talking about 15 percent of the population, or 100 percent if you consider that no one's getting through adulthood without going through their twenties first.

我们在讨论总人口的15%，或者你这样想，所有人都要经过他们20多岁才能进入成年。

How came he to think that he had arrived in London on Saturday, the twenty–first day of December, when it was really Friday, the twentieth, the seventy–ninth day only from his departure?

他到达伦敦的时候本来是12月20号，星期五，离开他出发的时间才只七十九天，可是他怎会以为已经是12月21号星期六晚上了呢？