The first step uses a bit of influenza DNA to get the patient's immune system to begin fighting off the flu, and then the protection is given a "boost" some time later by the second step, which can be either another bit of DNA or a conventional flu vaccine.

VOA: standard.2010.07.21

DNA also has this sort of combinatorial system where you have a finite number of, I guess, bases or amino acids that could combine to a possible infinity of strings of DNA strings.

脱氧核糖核酸也拥有这种组合系统,你的生物基础或氨基酸数量是有限的,但却能组合出,几乎无限的脱氧核糖核酸螺旋结构

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