是在一本动物学课本《integrated principles of Zoology》上，现在已经出到第十二版了，可是还是保留了十多年前我见到的一个老版本里的一张照片，上面是若干愤青状的家伙义愤填膺的样子，当中的一个端个牌子上书Stop animal research!
照片的上方，有如下黑体评论：Thanks to animal research, they'll be able to protest 20.8 years longer.
下面有小字说明：According to the U.S.Department of Health and Human Services, animal research has helped extend our life expectancy by 20.8 years.