Because it takes three units where there's only four choices at each position to have at least 20 unique combinations.

因为每个位点上仅有四种可能性,只有采用三个碱基一组,才能取得至少二十种不同的组合方式

耶鲁公开课 - 生物医学工程探索课程节选

The finding, which is not a subtle finding, is that liking goes up in the three group and liking goes down in the ten group.

虽然此研究的发现并不精确，但它却表明,在列举三个特征的组里,喜爱程度有所提高,而在列举十个特征的组里,喜爱程度有所下降。

耶鲁公开课 - 心理学导论课程节选

Here's a group of sounds, different pitches and actually three different pitches in there, as opposed to just one pitch--one pitch, three pitches or three or four pitches, moving in different ways, kind of independent rhythmic chords, so that's the difference between monophonic, homophonic and polyphonic texture.

这是一组音,不同的音高,事实上三个不同的音高,相对于一个音高,一个音高,三个音高或四个音高,以不同方式运动,像有独立节奏的和弦,这就是单音,主音和复音织体的区别

耶鲁公开课 - 聆听音乐课程节选

You know that messenger RNA is read in three base units called codons, and so this particular piece of messenger RNA is drawn in this cartoon in three base pair units.

RNA是按每三个碱基组成一个密码子,进行翻译的,在这幅动画中所画的mRNA,就是按三个碱基一组的方式来描绘的

耶鲁公开课 - 生物医学工程探索课程节选