It desertions among them, brood only additionally two.它丢掉其中一只, 只孵另外两只.Vapor jetted from the brood hose as from a little steam engine.大鼻子里象小小的蒸气机似的冒出热气....a large brood of children.一大群子女I continued to brood. Would he alwa...
传统的刀耕火种农业方式耗尽了土地的肥力。Traditional slash and burn farming methods have exhausted the soil.为保持土壤肥力,农民搞作物轮作.Farmers rotate their crops so that the soil will remain fertile.蚯蚓吃下大量土壤，排出肥力丰富、物理结构理想的腐殖质。Earthworms consume large a...