I'm going to begin at the bottom of 73: If you have your book, go ahead and open it up.

我将从73页最下面开始读：,如果你带了书，那么就打开书翻到那页。

耶鲁公开课 - 1945年后的美国小说课程节选

If you look at the electronegativity difference 73 for sodium iodide, it is 1.73.

如果你看到电负性之差,对碘化钠来说，是1。

麻省理工公开课 - 固态化学导论课程节选