Crossing over The exchange of material between homologous chromatids by the formation of chiasmata.交换:同源染色单体之间形成交叉时遗传物质的交换现象.The exchange of prisoners of war was one of the key elements of the UN's peace plan.交换战俘是联...
Man does not live by bread alone.人不能单靠面包生存....a thick hunk of bread.厚厚一大块面包There's not a living soul in Colorado who doesn't depend for his bread on silver.科罗拉多的每一个人都是靠着开采银矿养家糊口。Cut the salmon into long strips ...