natural crossing

• 自然交配

natural crossing的用法和样例：

例句

1. Former chicken of black blood chicken plants forest is by pure Hei Yu pheasant and the distinctive chicken that form after grouse is natural and copulatory are planted.
   丛林黑血鸡原鸡种是由纯黑羽山鸡与野鸡自然交配后形成的独特鸡种。
2. Hybrids are produced by the unnatural crossing of two species.
   杂交种是由两个物种非自然杂交产生的。