The difficulty in distinguishing variable species is largely due to the varieties mocking, as it were, other species of the same genus . 变异的物种所以难于区别,主要在于变种和同属中其他物种相象的缘故。
To our knowledge, the effect of genetic variation in leaf angle and dispersion has not been adequately quantified in trees . 据我们所知,在叶片角度和分布上遗传变异的效应,在树木中还没有被适当地定量研究过。
Analysis of 23 patients with measles clinical variation 23例麻疹病人临床变异的分析
Preliminary study on the variations of homo erectus in china 中国直立人变异的初步研究
A protease is key to the replication of the virus 蛋白酶是阻止非典病毒变异的关键物质。