HIV is a member of the family of viruses called retroviruses, and retroviruses all use RNA as their genetic material.

IV是一种逆转录病毒,所有逆转录病毒均以RNA作为遗传物质

耶鲁公开课 - 生物医学工程探索课程节选

Okay. Now watch what happens as we continue with this I,VI,IV,V,I progression.

好，在这一段I-VI-IV-V级的和弦进行后，音乐发生了什么变化呢。

耶鲁公开课 - 聆听音乐课程节选

An SIV is a company of a sort that invests in assets and they issue something like asset-backed commercial paper, but it's not a real company because it only exists as an organization sponsored by some bank.

IV类似从事资产投资的公司,同时也发行类似资产担保商业票据的证券,但它不是一家真正的公司,因为它只是由某家银行建立的一个组织

耶鲁公开课 - 金融市场课程节选

Then we'll come to a V chord, to a I chord,to a IV chord,to a V chord,to a I chord, just as we were doing with the Beach Boys.

然后出现了一个V级和弦，转到I级和弦，再到V级和弦，再到I级和弦，和我们刚才分析的Beach，Boys的一样。

耶鲁公开课 - 聆听音乐课程节选