... primary source : 原始来源，实级来源，第一手来源 source of variability : 变异性来源 source of variation : 变差来源；变异来源 ...
双语例句
1
Of course, solar activity is just one natural sourceof climate variability. Volcanic eruptions are another, spewing gas and dust into the atmosphere.
当然，太阳活动仅仅是气候变化的一个自然因素，火山喷发出气体和尘埃进入大气层也会带来这个结果。
2
At the same time, by enlarging the sourceof parents and adopting composite crosses, the defects of low genetic variability and genetic uniformity of low gossypol cotton can be overcomed.