So that's just a little bit of a check for yourself, and it should make sense because what you're doing is you're calculating the difference between energy levels, so you just need to flip around which you put first to end up with a positive number here, and that's a little bit of a check that you can do what yourself.

所以你们总要确保括号，离得这项是正的，这是你们自己,可以做的检查，这事很有道理的，因为你们做的是计算能量差,所以你需要调整顺序来保证一个正数，这是你们自己可以做的检查。

麻省理工公开课 - 化学原理课程节选

Every cell in your body has exactly the same DNA; that is if I could stretch out all the DNA and look at the base pair sequence, the sequences of bases along all the DNA in your chromosomes, they'd be identical in all the cells.

身体内每一个细胞都有完全相同的DNA,如果我把整条DNA展开,然后检查其碱基对的顺序,你体内每个细胞中染色体上,DNA的碱基对顺序,都是完全相同的

耶鲁公开课 - 生物医学工程探索课程节选