By statute, 3 is the magic number.

根据条例 犯下三起案件即连环杀手

And today we're going to talk about how some

今天我们要谈的是

and so we're genetically--we're very good at dividing by three,

因此我们天生对除以三的计算很熟练

This math teacher taught us about--

这个数学老师教我们

and somebody in the 1930s,

二十世纪三十年代

A guy called Donald Greer said,

一个叫唐纳·德格里尔人说

our records of incomes in England in 1380 are?

1380年英格兰的收入记录有多精确呢

but it's probably not far off.

不过可能差的也并不远

For each of these,

对于其中的每一种物质

For example, where do we want to--what do we want to limit--

如果我们想要限制某些营养物质的摄入

My mother's a doctor and my dad's an economist.

我母亲是医生 我父亲是经济学家

and this is not incidental, folks--

这不是偶然的